There is a relationship between the part of the country and the types of vegetables that grow best.
What is the explanatory and response variable in this situation?
2 points
2
Question 2
2.
Two friends attend different schools and are curious if there is an association between day of the week and whether homework is assigned in math class. For a semester they track if they have homework each day of the week. The segmented bar charts display the frequency with which homework is assigned each day of the week during this semester:
Is there an association between day of the week and how frequently homework is assigned for Nathan's or Lynn's schools?
How do you know there is an association? Select both answers.
Required
0 points
0
Question 3
3.
Researchers interested in the relationship between height and age collected data from randomly selected individuals.
The scatterplot displays the observed relationship.
Which of the following statements is true?
Required
4 points
4
Question 4
4.
Researchers interested in the relationship between height and weight collected data from randomly selected individuals.
The scatterplot displays the observed relationship.
Check the three conditions, is it appropriate to calculate the correlation for the relationship between age and height?
Check all four answers.
Required
2 points
2
Question 5
5.
Which of the following scatterplots is a correlation of 0.785?
Required
2 points
2
Question 6
6.
A scatterplot displayed a roughly linear relationship between miles run per week in practice and the time required to finish a race for a random sample of 25 cross country runners from a recent meet.
The correlation for this relationship was found to be -0.89.
What is the interpretation of the correlation?
Required
2 points
2
Question 7
7.
A cross-country runer collects data on his weekly practice and performance during races. He notices that the relationship between miles run the week before a race and his race time have a correlation of -0.97.
Which of the following is an INCORRECT conclusion about the relationship between weekly practice and race performance?
Required
0 points
0
Question 8
8.
A politician wants to know if there is a relationship between the amount of time he spent holding rallies in a city and the percent of votes he received from voters in that city. The results for 9 cities are shown in the scatterplot below.
The correlation between time and percent of votes is r=-0.121.
Which of the following is correct?
Required
2 points
2
Question 9
9.
The scatterplots both have outliers:
How do the outliers affect the correlation?
Required
2 points
2
Question 10
10.
A student taking an upper level math needed a more advanced calculator. Ebay.com had several auctions for the calculator.
The time remaining in the auctions and the current bid price were recorded.
Here is the scatterplot of the data, along with the equation of the regression line:
What is the predicted bid price for a calculator with half an hour remaining on the auction?
Hint: half an hour = how many minutes?
Required
2 points
2
Question 11
11.
A student taking a statistics class and needed a more advanced calculator. She collected selling price and number of bids received from Ebay.com on the same model of calculator she needs to purchase.
The equation of the regression line is:
How are the variables being used?
Required
3 points
3
Question 12
12.
A student taking a statistics class and needed a more advanced calculator. She collected selling price and number of bids received from Ebay.com on the same model of calculator she needs to purchase.
The equation of the regression line is:
Calculate and interpret the residual for a calculator that received 12 bids and sold for $60.
Select 3 answers.
Required
2 points
2
Question 13
13.
A student taking a statistics needed a more advanced calculator. Ebay.com had several auctions for the calculator.
The time remaining in the auctions and the current bid price were recorded.
The equation for the least-squares regression line is:
What is the slope and the interpretation of the slope?
Required
2 points
2
Question 14
14.
A student taking a statistics needed a more advanced calculator. Ebay.com had several auctions for the calculator.
The time remaining in the auctions and the current bid price were recorded.
The equation for the least-squares regression line is:
What is the y intercept and the interpretation of the y intercept?
Required
0 points
0
Question 15
15.
Scatterplot A displays sth relationship between two variables x and y.
Scatterplots B and C display the same relationship with an extra point added to each.
The least squares regression line has been draw on Scatterplot A for reference.
Which of the following is correct?
Required
2 points
2
Question 16
16.
Here are three residual plots from a Least-Squares Regression Equation:
Which of the residual plots indicate that the linear regression model is appropriate?
Required
0 points
0
Question 17
17.
A quadratic and exponential were calculated for the relationship between two variables, x and y. Here are the residual plots for these models:
Based on the residual plots, which model is more appropriate?
Required
3 points
3
Question 18
18.
Is there a relationship between gender and bedtime? It is suspected that females are more likely to have an earlier bedtime than males. A random sample was collected.
The two-way table displays the data:
What are the explanatory and response variables?
Required
2 points
2
Question 19
19.
Is there a relationship between gender and bedtime? It is suspected that females are more likely to have an earlier bedtime than males. A random sample was collected.
The two-way table displays the data:
Does it make sense to calculate the correlation coefficient for the data?
Select both answers.
Required
2 points
2
Question 20
20.
A professor was curious about the relationship between absencees and final grades in his introductory statistics course.
Use statsmedic.com/applets (2 quantitative variables) to create and observe a scatterplot.
What is the relationship between absences and final grades? Include the correlation coefficient and interpret it.
Required
2 points
2
Question 21
21.
Use the data from #20, have statsmedic.com/applets create a least-squares regression line for you. Enter the equation in the space below. Keep all decimal places.
Be sure to use -hat to show which variable is being predicted.
Use these names for the variables: absences grade
Required
2 points
2
Question 22
22.
Use the equation from #21 to predict the final grade for a student with 4 absences.
Round your answer to two places past the decimal point. No units necessary.
Required
2 points
2
Question 23
23.
Using your answer from #22 for the predicted final grade and the actual final grade of 85.3 for a student with 4 absences, calculate the residual:
Enter your answer and tell if the model over or under predicted the final grade.
Required
2 points
2
Question 24
24.
Would you feel comfortable using this model to predict the final grade for a student with 19 absences? Why or why not?
Think about what we discussed in class and what this is called.
Required
2 points
2
Question 25
25.
Look back at the residual plot in statsmedic, what does it tell you?
0 points
0
Question 26
26.
BONUS
The scatterplot displays the relationship between height and field-goal percentage for all the basketball players on the 2013 roster of the Brooklyn Nets.
The equation of the regression line is:
A. 2 points: Interpret the y-intercept. Make sure to tell if it has meaning in this situation.