2023 Fall Semester Exam Review Statistics

Last updated almost 2 years ago

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Library

2023 Fall Semester Exam Review Statistics

Last updated almost 2 years ago

33 questions

Chapter 1

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The dotplots show the total family income of 40 randomly chosen individuals each from Connecticut, Indiana, and Maine, based on U.S. Census data.

Which graph has a higher standard deviation?
ie. Which graph has greater variability?

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The dotplots show the total family income of 40 randomly chosen individuals each from Connecticut, Indiana, and Maine, based on U.S. Census data.

Which graph has a shape that is closest to being roughly symmetric?

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The dotplots show the total family income of 40 randomly chosen individuals each from Connecticut, Indiana, and Maine, based on U.S. Census data.

Which graph has the lowest mean?

Chapter 2

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Find the interquartile range of the data in #9.

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The following dotplot gives the sale prices for 40 houses in Ames, Iowa, sold during a recent month. The mean sale price was $203,388 with a standard deviation of $87,609.

Find the percentile of the house that is indicated on the dotplot. Remember percentile means the percent to the LEFT of a value.

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Continue with the information from above:
The equation of the regression line relating these variables is

Los Angeles, California, is at latitude 34º and actually has a mean July temperature of 74º.
Calculate the predicted temperature value for July.
Keep all places past the decimal point, no units.

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Use the information from above:

Los Angeles, California, is at latitude 34º and actually has a mean July temperature of 74º.

Calculate the residual for the July prediction. Keep all decimal points, no units.

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Chapter 3

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Chapter 1

Here is some information about the first 10 U.S. presidents. Identify the individuals and variables in this data set. Classify each variable as categorical or quantitative.

State of Birth
Name
Age at Inauguration
Political Party
Age at Death

Categorical Variable
Quantitative Variable

The dotplot below displays shows the scores of 21 Statistics students on a 20-point quiz.

What does one dot represent?

The answer to one of the questions on the 20 point quiz.

One person's score out of 20 points.

The class average score out of 21 students.

The dotplot below displays shows the scores of 21 Statistics students on a 20-point quiz.

a) Describe the shape of the distribution.
b) How does the mean compare to the median?

The dotplot below displays shows the scores of 21 Statistics students on a 20-point quiz.

a) Using the dot plot above, what is the appropriate measure of center and spread?
b) Why would you choose these?

the skew pulls the mean to the right

median & standard deviation

mean & IQR

the skew pulls the mean to the left

the mean & Std Dev are resistant to the skew & outliers, they don't get pulled to the left.

the median & IQR are resistant to the skew & outliers, they don't get pulled to the left.

mean & standard deviation

median & IQR

Do you “binge-watch” television series by viewing multiple episodes of a series at one sitting? A survey of 800 people who “binge-watch” were asked how many episodes is too many to watch in one viewing session.
The results are displayed in the bar chart.

Explain how this graph is misleading.

The scale on the y axis causes the reader to think that the 'there is no too many' is half as frequent as the '5 to 6' column.

All the colors make it confusing to read.

The scale on the y axis causes the reader to think '5 to 6' is about 10x more frequent than '3 to 4'.

The 'there is no too many' should be listed first since it doesn't include a number.

The graph is not misleading at all.

The dotplots show the total family income of 40 randomly chosen individuals each from Connecticut, Indiana, and Maine, based on U.S. Census data.

Which graph has a higher standard deviation?
ie. Which graph has greater variability?

The dotplots show the total family income of 40 randomly chosen individuals each from Connecticut, Indiana, and Maine, based on U.S. Census data.

Which graph has a shape that is closest to being roughly symmetric?

The dotplots show the total family income of 40 randomly chosen individuals each from Connecticut, Indiana, and Maine, based on U.S. Census data.

Which graph has the lowest mean?

Chapter 2

For a project in their statistics class, Alex and Tempe studied the impact of different types of background music on students’ ability to remember words from a list they were allowed to study for 5 min. Here is a list of how many words one group of students who listened to Beethoven’s Fifth Symphony were able to remember.
11   12   23   15   14   15   14   15
10   14   15   9   11   13   25   11
13   13   12   20   17   23   11   12
12   11   20   20   12   12   19   13
15   10   14   11   7   17   13   18

Use statsmedic.com/applets, 1 quantitative variable. Make a histogram that effectively displays the distribution of words recalled.
Describe the histogram using D.O.F.S.

We used technology to compute the mean and median of the distribution.
One is 13 and the other is 14.3.
Based on the histogram from #9, explain how you know which is which without doing any calculations.

The median is 13 and the mean is 14.3 because the outliers pull the mean higher.

The mean is 13 and the median is 14.3 because the outliers pull the mean higher.

The mean is 13 and the median is 14.3 because the outliers pull the mean lower.

The median is 13 and the mean is 14.3 because the outliers pull the mean lower.

Using the same histogram from #9, what effect would removing the outliers have on the mean & standard deviation?

The mean would decrease and the standard deviation would decrease.

The mean would increase and the standard deviation would increase.

The mean would decrease and the standard deviation would increase.

The mean would increase and the standard deviation would decrease.

Find the interquartile range of the data in #9.

The standard deviation is 4.05.
Interpret this value in context.

The data values are typically 4.05 from the mean.

The data values are 4.05 above the minimum.

The data values are typically 4.05 apart from each other.

The data values are 4.05 from the maximum.

The following dotplot gives the sale prices for 40 houses in Ames, Iowa, sold during a recent month. The mean sale price was $203,388 with a standard deviation of $87,609.

Find the percentile of the house that is indicated on the dotplot. Remember percentile means the percent to the LEFT of a value.

At what age do babies learn to crawl? Does it take longer to learn in the winter, when babies are often bundled in clothes that restrict movement? There might even be an association between babies’ crawling age and the average temperature during the month when they first try to crawl (around 6 months after birth).
Data were collected from parents who reported the birth month and the age at which their child was first able to creep or crawl a distance of 4 feet within 1 minute. Information was obtained on 414 infants, 208 boys and 206 girls.
Average crawling age is given in weeks, and the average temperature (in degrees Fahrenheit) is for the month that is 6 months after the birth month.
Copy and paste the data into statsmedic.com/applets, 2 quantitative variables.

Birth Month: Jan. Feb. Mar. Apr. May. Jun. July. Aug. Sept. Oct. Nov. Dec.
Ave. Temp.: 66 73 73 63 52 39 33 30 33 37 48 57
Ave. Age: 29.84 30.52 29.7 31.84 28.58 31.44 33.64 32.82 33.83 33.35 33.38 32.32

Work with a partner, use statsmedic.com to make a scatterplot to display the relationship between average 6-month temperature and average crawling age.

Describe the relationship shown in the scatterplot.
Select all that apply.
If you're not sure of the strength, calculate the correlation.

What does a correlation coefficient tell us?

The direction only of a relationship.

The strength and direction of a linear relationship.

The strength only of a relationship.

The strength, direction and form of  relationship.

How would the correlation value change if the age of crawling was entered in days?

The correlation (r) would get weaker.

The correlation (r) value would not change.

It is difficult to determine what the affect would be.

The correlation (r) would get stronger.

Using your scatterplot from above:

a) Describe what is unusual about the point representing May.

b) How does the point representing May affect the equation of the least-squares regression line? Explain.

The point representing May is an outlier, it is outside the pattern of the data.

The point representing May causes the slope to be more negative and

the y-intercept to be lower.

The point representing May is not an outlier, it's not too far out of the pattern of the data.

The point representing May causes the slope to be less negative and

the y-intercept to be higher.

Using your scatterplot, if the point representing May was removed, how would that affect the equation of the least-squares regression line? Explain.

the y-intercept would become smaller.

If the point representing May was removed the slope of the regression equation would not change and

If the point representing May was removed the slope of the regression equation would become more negative and

If the point representing May was removed the slope of the regression equation would become less negative and

the y-intercept would become larger.

The principal of a high school read a study that reported a positive correlation between the number of calculators owned by high school students and their math achievement. Based on this study, he decides to buy each student at his school 2 calculators, hoping to improve their math achievement.
Explain the flaw in the principal’s reasoning.

The calculators caused the students to do better on their math tests and SAT tests showing higher achievement.

Owning a calculator is associated with higher math scores by students.

The principal's thinking is not flawed.

Owning a calculator causes a students' math scores to improve.

The principal's thinking is flawed because he assumes the calculators caused an improved math achievement.

The scatterplot shows the relationship between latitude and mean July temperature (in degrees Fahrenheit) for 12 cities in the United States.

If you were to predict the mean July temperature in Fairbanks, Alaska, at latitude 65º, how confident would you be in this prediction?

Very confident

we would use the linear regression equation to find the mean July temperature.

we would be extrapolating so the calculations would be risky.

Not very confident

Continue with the information from above:
The equation of the regression line relating these variables is

Los Angeles, California, is at latitude 34º and actually has a mean July temperature of 74º.
Calculate the predicted temperature value for July.
Keep all places past the decimal point, no units.

Use the information from above:

Los Angeles, California, is at latitude 34º and actually has a mean July temperature of 74º.

Calculate the residual for the July prediction. Keep all decimal points, no units.

Use the information from the regression model:

Interpret the slope of the regression line.

For every temperature increase in degree the latitude goes up 0.782 degrees

For every degree increase in latitude the temperature goes up 0.782 degrees

For every degree increase in latitude the temperature goes down 0.782 degrees

For every temperature decrease in degree the latitude goes down 0.782 degrees

Use the information from above:
Does the value of the y intercept have meaning in this context?
If so, interpret the y intercept. If not, explain why.

The y intercept has meaning in this context

The y intercept does not have meaning in this context

it is the temperature when the latitude is zero, at the equator.

it is the latitude when the temperature is zero, at the north pole.

We used a least-squares regression line to model the relationship between x = latitude
and y = mean July temperature (in degrees Fahrenheit) for a sample of 12 cities in the United States. Here is the residual plot for this model.

Explain what the residual plot suggests about the appropriateness of the linear model.

this indicates that the linear model is not appropriate.

The residual plot shows a strong pattern,

this indicates that the linear model is appropriate.

The residual plot shows random scatter,

Chapter 3

Indicate the following is a valid statistical question. Explain your reasoning.

'How many people visited Acadia National Park last Tuesday?'

Not a valid statistical question

Valid statistical question

the answer gives varied answers.

the answer does not give varied answers.

Indicate if the following is a valid statistical question. Explain your reasoning.

'How many people visit Acadia National Park on a typical weekday in August?'

Valid statistical question

Not a valid statistical question

it does not give answers that are varied.

it gives answers that are varied.

In a recent study of a random sample of 250 U.S. residents, it was found that 85% rated the honesty and ethical standards of nurses as very high or high.

Do you think that the proportion of all U.S. residents who rate the honesty and ethical standards of nurses as very high or high is exactly 0.85? Explain.

Yes, the proportion of all U.S. residents who rate the honesty and ethical standards of nurses as very high or high is exactly 0.85.

This cannot be determined without doing a very large randomized study.

due to sampling variability we know 85% is the exact value.

No, the proportion of all U.S. residents who rate the honesty and ethical standards of nurses as very high or high is not exactly 0.85 but it is close.

due to sampling variability we know that 85% is not exact but is close.

Use the previous question information:
If the size of a sample in the poll was increased to 1250 residents, what effect would this have on the variability? Explain.

The variability would increase because

the sample size increased.

The variability would decrease because

the sample size decreased.

The variability would not change because

the sample size did not change.

The administration at a high school with 1800 students wants to gather student opinion about parking for students on campus. It isn’t practical to contact all students.

Send an email to all the students and ask them to fill out the survey online.
Number all students in the school, use a random number generator to draw 50 numbers, survey those corresponding students.
Stand at the doors to the courtyard and by the bus drop off and survey students as they enter the school.

Voluntary Response Sample
Convenience Sample
Simple Random Sample (SRS)

An opinion poll calls 2000 randomly chosen residential telephone numbers, then asks to speak with an adult member of the household.
The interviewer asks, “Box-office revenues are at an all-time high. How many movies have you watched in a movie theater in the past 12 months?”
In all, 1131 people responded. The researchers used the responses to estimate the mean number of movies adults have watched in a movie theater in the past 12 months.

Categorize the types of bias with the descriptions.

Using only residential phone numbers to contact the sample to be surveyed
Wording of the question could cause people to be more likely to respond favorable
2000 Randomly chosen phone numbers were called, response from 1131 people were received.

Response Bias
Undercoverage Bias
Nonresponse Bias

A recent random sample of n = 805 adult U.S. residents found that the proportion who rated the honesty and ethical standards of nurses as very high or high is 0.85.
This is 0.15 higher than the proportion recorded for doctors, the next highest-ranked profession.

Identify the sample and the population in this setting.

the sample is U.S. residents.

The population is all U.S. residents and

the sample is 0.85 U.S. residents.

the sample is 805 adult U.S. residents.

The population is 805 U.S. residents and

Here is some information about the first 10 U.S. presidents. Identify the individuals and variables in this data set. Classify each variable as categorical or quantitative.

State of Birth

Name

Age at Inauguration

Political Party

Age at Death

Categorical Variable

Quantitative Variable

The dotplot below displays shows the scores of 21 Statistics students on a 20-point quiz.

What does one dot represent?

The answer to one of the questions on the 20 point quiz.

One person's score out of 20 points.

The class average score out of 21 students.

The dotplot below displays shows the scores of 21 Statistics students on a 20-point quiz.

a) Describe the shape of the distribution.
b) How does the mean compare to the median?

mean = median

Roughly symmetric

mean < median

mean > median

Skewed left

Skewed right

The dotplot below displays shows the scores of 21 Statistics students on a 20-point quiz.

a) Using the dot plot above, what is the appropriate measure of center and spread?
b) Why would you choose these?

the skew pulls the mean to the right

median & standard deviation

mean & IQR

the skew pulls the mean to the left

the mean & Std Dev are resistant to the skew & outliers, they don't get pulled to the left.

the median & IQR are resistant to the skew & outliers, they don't get pulled to the left.

mean & standard deviation

median & IQR

Do you “binge-watch” television series by viewing multiple episodes of a series at one sitting? A survey of 800 people who “binge-watch” were asked how many episodes is too many to watch in one viewing session. 
The results are displayed in the bar chart. 


Explain how this graph is misleading.

The scale on the y axis causes the reader to think that the 'there is no too many' is half as frequent as the '5 to 6' column.

All the colors make it confusing to read.

The scale on the y axis causes the reader to think '5 to 6' is about 10x more frequent than '3 to 4'.

The 'there is no too many' should be listed first since it doesn't include a number.

The graph is not misleading at all.

For a project in their statistics class, Alex and Tempe studied the impact of different types of background music on students’ ability to remember words from a list they were allowed to study for 5 min. Here is a list of how many words one group of students who listened to Beethoven’s Fifth Symphony were able to remember.
11   12   23   15   14   15   14   15
10   14   15   9   11   13   25   11
13   13   12   20   17   23   11   12
12   11   20   20   12   12   19   13
15   10   14   11   7   17   13   18

Use statsmedic.com/applets, 1 quantitative variable. Make a histogram that effectively displays the distribution of words recalled.
Describe the histogram using D.O.F.S.

There are outliers to the left

Roughly symmetric

Range of about 16

Center about 11 or 12

There are no outliers

There are outliers to the right

Center about 15

Range of about 18

Right skewed

Left skewed

We used technology to compute the mean and median of the distribution. 
One is 13 and the other is 14.3. 
Based on the histogram from #9, explain how you know which is which without doing any calculations.

The median is 13 and the mean is 14.3 because the outliers pull the mean higher.

The mean is 13 and the median is 14.3 because the outliers pull the mean higher.

The mean is 13 and the median is 14.3 because the outliers pull the mean lower.

The median is 13 and the mean is 14.3 because the outliers pull the mean lower.

Using the same histogram from #9, what effect would removing the outliers have on the mean & standard deviation?

The mean would decrease and the standard deviation would decrease.

The mean would increase and the standard deviation would increase.

The mean would decrease and the standard deviation would increase.

The mean would increase and the standard deviation would decrease.

The standard deviation is 4.05. 
Interpret this value in context.

The data values are typically 4.05 from the mean.

The data values are 4.05 above the minimum.

The data values are typically 4.05 apart from each other.

The data values are 4.05 from the maximum.

At what age do babies learn to crawl? Does it take longer to learn in the winter, when babies are often bundled in clothes that restrict movement? There might even be an association between babies’ crawling age and the average temperature during the month when they first try to crawl (around 6 months after birth). 
Data were collected from parents who reported the birth month and the age at which their child was first able to creep or crawl a distance of 4 feet within 1 minute. Information was obtained on 414 infants, 208 boys and 206 girls. 
Average crawling age is given in weeks, and the average temperature (in degrees Fahrenheit) is for the month that is 6 months after the birth month.
Copy and paste the data into statsmedic.com/applets, 2 quantitative variables.

Birth Month: Jan.    Feb.     Mar.    Apr.     May.     Jun.    July.    Aug.    Sept.    Oct.    Nov.    Dec. 
Ave. Temp.:    66      73         73       63         52         39       33       30        33         37        48        57
Ave. Age:      29.84  30.52   29.7   31.84   28.58   31.44   33.64  32.82   33.83   33.35   33.38  32.32

Work with a partner, use statsmedic.com to make a scatterplot to display the relationship between average 6-month temperature and average crawling age. 

Describe the relationship shown in the scatterplot.
Select all that apply.
If you're not sure of the strength, calculate the correlation.

Negative

Positive

No direction

linear

nonlinear

moderate relationship

strong relationship

weak relationship

What does a correlation coefficient tell us?

The direction only of a relationship.

The strength and direction of a linear relationship.

The strength only of a relationship.

The strength, direction and form of  relationship.

How would the correlation value change if the age of crawling was entered in days?

The correlation (r) would get weaker.

The correlation (r) value would not change.

It is difficult to determine what the affect would be.

The correlation (r) would get stronger.

Using your scatterplot from above:

a)  Describe what is unusual about the point representing May.

b) How does the point representing May affect the equation of the least-squares regression line? Explain.

The point representing May is an outlier, it is outside the pattern of the data.

The point representing May causes the slope to be more negative and

the y-intercept to be lower.

The point representing May is not an outlier, it's not too far out of the pattern of the data.

The point representing May causes the slope to be less negative and

the y-intercept to be higher.

Using your scatterplot, if the point representing May was removed, how would that affect the equation of the least-squares regression line? Explain.

the y-intercept would become smaller.

If the point representing May was removed the slope of the regression equation would not change and

If the point representing May was removed the slope of the regression equation would become more negative and

If the point representing May was removed the slope of the regression equation would become less negative and

the y-intercept would become larger.

The principal of a high school read a study that reported a positive correlation between the number of calculators owned by high school students and their math achievement. Based on this study, he decides to buy each student at his school 2 calculators, hoping to improve their math achievement. 
Explain the flaw in the principal’s reasoning.

The calculators caused the students to do better on their math tests and SAT tests showing higher achievement.

Owning a calculator is associated with higher math scores by students.

The principal's thinking is not flawed.

Owning a calculator causes a students' math scores to improve.

The principal's thinking is flawed because he assumes the calculators caused an improved math achievement.

The scatterplot shows the relationship between latitude and mean July temperature (in degrees Fahrenheit) for 12 cities in the United States.

If you were to predict the mean July temperature in Fairbanks, Alaska, at latitude 65º, how confident would you be in this prediction? 

Very confident

we would use the linear regression equation to find the mean July temperature.

we would be extrapolating so the calculations would be risky.

Not very confident

Use the information from the regression model:

Interpret the slope of the regression line.

For every temperature increase in degree the latitude goes up 0.782 degrees

For every degree increase in latitude the temperature goes up 0.782 degrees

For every degree increase in latitude the temperature goes down 0.782 degrees

For every temperature decrease in degree the latitude goes down 0.782 degrees

Use the information from above:
Does the value of the y intercept have meaning in this context? 
If so, interpret the y intercept. If not, explain why.

The y intercept has meaning in this context

The y intercept does not have meaning in this context

it is the temperature when the latitude is zero, at the equator.

it is the latitude when the temperature is zero, at the north pole.

We used a least-squares regression line to model the relationship between x = latitude 
and y = mean July temperature (in degrees Fahrenheit) for a sample of 12 cities in the United States. Here is the residual plot for this model.


Explain what the residual plot suggests about the appropriateness of the linear model.

this indicates that the linear model is not appropriate.

The residual plot shows a strong pattern,

this indicates that the linear model is appropriate.

The residual plot shows random scatter,

Indicate the following is a valid statistical question. Explain your reasoning.

'How many people visited Acadia National Park last Tuesday?'

Not a valid statistical question

Valid statistical question

the answer gives varied answers.

the answer does not give varied answers.

Indicate if the following is a valid statistical question. Explain your reasoning.

'How many people visit Acadia National Park on a typical weekday in August?'

Valid statistical question

Not a valid statistical question

it does not give answers that are varied.

it gives answers that are varied.

In a recent study of a random sample of 250 U.S. residents, it was found that 85% rated the honesty and ethical standards of nurses as very high or high.

Do you think that the proportion of all U.S. residents who rate the honesty and ethical standards of nurses as very high or high is exactly 0.85? Explain.

Yes, the proportion of all U.S. residents who rate the honesty and ethical standards of nurses as very high or high is exactly 0.85.

This cannot be determined without doing a very large randomized study.

due to sampling variability we know 85% is the exact value.

No, the proportion of all U.S. residents who rate the honesty and ethical standards of nurses as very high or high is not exactly 0.85 but it is close.

due to sampling variability we know that 85% is not exact but is close.

Use the previous question information:
If the size of a sample in the poll was increased to 1250 residents, what effect would this have on the variability? Explain.

The variability would increase because

the sample size increased.

The variability would decrease because

the sample size decreased.

The variability would not change because

the sample size did not change.

The administration at a high school with 1800 students wants to gather student opinion about parking for students on campus. It isn’t practical to contact all students.

Send an email to all the students and ask them to fill out the survey online.

Number all students in the school, use a random number generator to draw 50 numbers, survey those corresponding students.

Stand at the doors to the courtyard and by the bus drop off and survey students as they enter the school.

Voluntary Response Sample

Convenience Sample

Simple Random Sample (SRS)

An opinion poll calls 2000 randomly chosen residential telephone numbers, then asks to speak with an adult member of the household. 
The interviewer asks, “Box-office revenues are at an all-time high. How many movies have you watched in a movie theater in the past 12 months?” 
In all, 1131 people responded. The researchers used the responses to estimate the mean number of movies adults have watched in a movie theater in the past 12 months.

Categorize the types of bias with the descriptions.

Using only residential phone numbers to contact the sample to be surveyed

Wording of the question could cause people to be more likely to respond favorable

2000 Randomly chosen phone numbers were called, response from 1131 people were received.

Response Bias

Undercoverage Bias

Nonresponse Bias

A recent random sample of n = 805 adult U.S. residents found that the proportion who rated the honesty and ethical standards of nurses as very high or high is 0.85. 
This is 0.15 higher than the proportion recorded for doctors, the next highest-ranked profession.

Identify the sample and the population in this setting.

the sample is U.S. residents.

The population is all U.S. residents and

the sample is 0.85 U.S. residents.

the sample is 805 adult U.S. residents.

The population is 805 U.S. residents and

2023 Fall Semester Exam Review Statistics

2023 Fall Semester Exam Review Statistics

Chapter 1

The dotplots show the total family income of 40 randomly chosen individuals each from Connecticut, Indiana, and Maine, based on U.S. Census data. Which graph has a higher standard deviation?ie. Which graph has greater variability?

The dotplots show the total family income of 40 randomly chosen individuals each from Connecticut, Indiana, and Maine, based on U.S. Census data. Which graph has a shape that is closest to being roughly symmetric?

The dotplots show the total family income of 40 randomly chosen individuals each from Connecticut, Indiana, and Maine, based on U.S. Census data. Which graph has the lowest mean?

Chapter 2

Find the interquartile range of the data in #9.

The following dotplot gives the sale prices for 40 houses in Ames, Iowa, sold during a recent month. The mean sale price was $203,388 with a standard deviation of $87,609.Find the percentile of the house that is indicated on the dotplot. Remember percentile means the percent to the LEFT of a value.

Use the information from above:Los Angeles, California, is at latitude 34º and actually has a mean July temperature of 74º. Calculate the residual for the July prediction. Keep all decimal points, no units.

Chapter 3

Chapter 1

Here is some information about the first 10 U.S. presidents. Identify the individuals and variables in this data set. Classify each variable as categorical or quantitative.

The dotplot below displays shows the scores of 21 Statistics students on a 20-point quiz.What does one dot represent?

The dotplot below displays shows the scores of 21 Statistics students on a 20-point quiz.a) Describe the shape of the distribution.b) How does the mean compare to the median?

The dotplot below displays shows the scores of 21 Statistics students on a 20-point quiz.a) Using the dot plot above, what is the appropriate measure of center and spread?b) Why would you choose these?

The dotplots show the total family income of 40 randomly chosen individuals each from Connecticut, Indiana, and Maine, based on U.S. Census data. Which graph has a higher standard deviation?ie. Which graph has greater variability?

The dotplots show the total family income of 40 randomly chosen individuals each from Connecticut, Indiana, and Maine, based on U.S. Census data. Which graph has a shape that is closest to being roughly symmetric?

The dotplots show the total family income of 40 randomly chosen individuals each from Connecticut, Indiana, and Maine, based on U.S. Census data. Which graph has the lowest mean?

Chapter 2

We used technology to compute the mean and median of the distribution. One is 13 and the other is 14.3. Based on the histogram from #9, explain how you know which is which without doing any calculations.

Using the same histogram from #9, what effect would removing the outliers have on the mean & standard deviation?

Find the interquartile range of the data in #9.

The standard deviation is 4.05. Interpret this value in context.

The following dotplot gives the sale prices for 40 houses in Ames, Iowa, sold during a recent month. The mean sale price was $203,388 with a standard deviation of $87,609.Find the percentile of the house that is indicated on the dotplot. Remember percentile means the percent to the LEFT of a value.

What does a correlation coefficient tell us?

How would the correlation value change if the age of crawling was entered in days?

Using your scatterplot from above:a) Describe what is unusual about the point representing May.b) How does the point representing May affect the equation of the least-squares regression line? Explain.

Using your scatterplot, if the point representing May was removed, how would that affect the equation of the least-squares regression line? Explain.

The scatterplot shows the relationship between latitude and mean July temperature (in degrees Fahrenheit) for 12 cities in the United States.If you were to predict the mean July temperature in Fairbanks, Alaska, at latitude 65º, how confident would you be in this prediction?

Use the information from above:Los Angeles, California, is at latitude 34º and actually has a mean July temperature of 74º. Calculate the residual for the July prediction. Keep all decimal points, no units.

Use the information from the regression model:Interpret the slope of the regression line.

Use the information from above:Does the value of the y intercept have meaning in this context? If so, interpret the y intercept. If not, explain why.

Chapter 3

Indicate the following is a valid statistical question. Explain your reasoning.'How many people visited Acadia National Park last Tuesday?'

Indicate if the following is a valid statistical question. Explain your reasoning.'How many people visit Acadia National Park on a typical weekday in August?'

Use the previous question information:If the size of a sample in the poll was increased to 1250 residents, what effect would this have on the variability? Explain.

The administration at a high school with 1800 students wants to gather student opinion about parking for students on campus. It isn’t practical to contact all students.

The dotplots show the total family income of 40 randomly chosen individuals each from Connecticut, Indiana, and Maine, based on U.S. Census data.

Which graph has a higher standard deviation?
ie. Which graph has greater variability?

The dotplots show the total family income of 40 randomly chosen individuals each from Connecticut, Indiana, and Maine, based on U.S. Census data.

Which graph has a shape that is closest to being roughly symmetric?

The dotplots show the total family income of 40 randomly chosen individuals each from Connecticut, Indiana, and Maine, based on U.S. Census data.

Which graph has the lowest mean?

Use the information from above:

Los Angeles, California, is at latitude 34º and actually has a mean July temperature of 74º.

Calculate the residual for the July prediction. Keep all decimal points, no units.

The dotplot below displays shows the scores of 21 Statistics students on a 20-point quiz.

What does one dot represent?

The dotplot below displays shows the scores of 21 Statistics students on a 20-point quiz.

a) Describe the shape of the distribution.
b) How does the mean compare to the median?

The dotplot below displays shows the scores of 21 Statistics students on a 20-point quiz.

a) Using the dot plot above, what is the appropriate measure of center and spread?
b) Why would you choose these?

The dotplots show the total family income of 40 randomly chosen individuals each from Connecticut, Indiana, and Maine, based on U.S. Census data.

Which graph has a higher standard deviation?
ie. Which graph has greater variability?

The dotplots show the total family income of 40 randomly chosen individuals each from Connecticut, Indiana, and Maine, based on U.S. Census data.

Which graph has a shape that is closest to being roughly symmetric?

The dotplots show the total family income of 40 randomly chosen individuals each from Connecticut, Indiana, and Maine, based on U.S. Census data.

Which graph has the lowest mean?

We used technology to compute the mean and median of the distribution.
One is 13 and the other is 14.3.
Based on the histogram from #9, explain how you know which is which without doing any calculations.

The standard deviation is 4.05.
Interpret this value in context.

Using your scatterplot from above:

a) Describe what is unusual about the point representing May.

b) How does the point representing May affect the equation of the least-squares regression line? Explain.

The scatterplot shows the relationship between latitude and mean July temperature (in degrees Fahrenheit) for 12 cities in the United States.

If you were to predict the mean July temperature in Fairbanks, Alaska, at latitude 65º, how confident would you be in this prediction?

Use the information from above:

Los Angeles, California, is at latitude 34º and actually has a mean July temperature of 74º.

Calculate the residual for the July prediction. Keep all decimal points, no units.

Use the information from the regression model:

Interpret the slope of the regression line.

Use the information from above:
Does the value of the y intercept have meaning in this context?
If so, interpret the y intercept. If not, explain why.

Indicate the following is a valid statistical question. Explain your reasoning.

'How many people visited Acadia National Park last Tuesday?'

Indicate if the following is a valid statistical question. Explain your reasoning.

'How many people visit Acadia National Park on a typical weekday in August?'

Use the previous question information:
If the size of a sample in the poll was increased to 1250 residents, what effect would this have on the variability? Explain.