Chapter 6 Review Due 3/26

Instructions

This review is optional but will give excellent practice for the test.

Required

4

A study of voting chose 663 registered voters at random shortly after an election. Of these, 72% said they had voted in the election. Election records show that only 56% of registered voters voted in the election.
Match up the following statements about these percentages?

Draggable item		Corresponding Item
663 regsitered voters		Parameter
72%		Statistic
All voters		Sample
56%		Population

Required

2

Vermont is particularly beautiful in early October when the leaves begin to change color. At that time of year, a large proportion of cars on Interstate 91 near Brattleboro have out-of-state license plates.
Suppose a Vermont state trooper randomly selects 50 cars driving past Exit 2 on I-91, records the state identified on the license plate, and calculates the proportion of cars with out-of-state plates.
What is the Vermont state trouper recording?
Which of the following describes the sampling distribution of the sample proportion in this context?

Required

2

A polling organization wants to estimate the proportion of voters who favor a new law banning smoking in public buildings.
The organization decides to increase the size of its random sample of voters from about 1500 people to about 4000 people right before an election.
The effect of this is to

Required

2

The central limit theorem is important in statistics because it allows us to use the normal distribution to find probabilities involving the sample mean if the

Required

3

At a high school, 85% of students are right-handed. 
Let X = the number of students who are right-handed in a random sample of 10 students from the school. 
What is the sample size? n= _______ 
What is the mean of the sampling distribution?  _______  enter as a proportion, not a percent.
What is the standard deviation of the sampling distribution?  _______  Round to three places past the decimal point.

Required

1

Using the information in the previous problem, what is the Normal Model?
Use the notation N(

Required

3

The student newspaper at a large university asks an SRS of 250 undergraduates, “Do you favor eliminating the carnival from the end-of-term celebration?”
In the sample, 150 of the 250 undergraduates are in favor.
Suppose that 55% of all undergraduates favor eliminating the carnival. If you took a very large number of SRSs of size n = 250 from this population, the sampling distribution of the sample proportion p-hat would have which of the following characteristics?

Required

4

Scores on the mathematics part of the SAT exam in a recent year followed a normal distribution with mean 515 and standard deviation 114.
You choose an SRS of 100 students and calculate mean SAT Math score.
Match up the following for this situation.

Draggable item		Corresponding Item
100		sample size (n)
114
11.4
515

Required

3

In a congressional district, 52% of the registered voters are Democrats. An SRS of 100 voters is going to be polled.
What is the mean of the sampling distribution of the sample proportion of democrat voters? _______ 

What is the standard deviation of the sampling distribution of the sample proportion of democrat voters? _______ Round to two places past the decimal.

What is the probability of getting less than 50% Democrats in a random sample of size 100?
_______  
.Keep your answer as the decimal proportion, keep all decimal places (there will be four)>

Required

1

Use the information in the previous question.
What is the probability of getting a sample of 100 registered voters with more than 65% democrats?
Keep all decimals.

Required

4

Using the information above, suppose an actual sample of 100 of the registered voters actually resulted in 65% democrats. Would you have convincing evidence that the estimated 52% democrat voters was incorrect? Explain.

Required

2

The amount that households pay service providers for access to the Internet varies quite a bit, but the mean monthly fee is $48 and the standard deviation is $20. 
The distribution is not normal: Many households pay a base rate for low-speed access, but some pay much more for faster connections so the distribution is strongly right skewed. 

A sample survey asks an SRS of 500 households with Internet access how much they pay per month. Let X-bar be the mean amount paid by the members of the sample.

Calculate the mean and standard deviation of the sampling distribution of the sample means. 
Sampling distribution sample mean = _______ 
Sampling distribution of sample means standard deviation = _______  
Round to three places past the decimal.

Required

3

Use the information from the previous question:
What is the shape of the population and the sampling distribution of x-bar ? Justify.

Required

2

Use the information in the previous two questions:
In a sampling distribution, find the probability that the average amount paid by the sample of households exceeds $50.

z-score = _______  round to two places past the decimal

Probability = _______ Keep the probability as a decimal proportion

Required

2

Use the information from the previous 3 questions:
In a sampling distribution, what is the probability that the average amount paid by the sample of households is less than $46.50.
z-score = _______   round to two places past the decimal

Probability = _______ Keep your answer as a decimal proportion.

Required

1

Match the correct notation with the definition.

Draggable item		Corresponding Item
		Population Mean
		Population Proportion
		Mean of the Sampling Distribution of Means
X-bar		Mean of the Sampling Distribution of Proportions
		Sample Mean
		Sample proportion
		Standard Deviation of the Sampling Distribution of means
p-hat		Standard Deviation of the Sampling Distribution of proportions

Chapter 6 Review Due 3/26

A study of voting chose 663 registered voters at random shortly after an election. Of these, 72% said they had voted in the election. Election records show that only 56% of registered voters voted in the election. Match up the following statements about these percentages?

A polling organization wants to estimate the proportion of voters who favor a new law banning smoking in public buildings. The organization decides to increase the size of its random sample of voters from about 1500 people to about 4000 people right before an election. The effect of this is to

The central limit theorem is important in statistics because it allows us to use the normal distribution to find probabilities involving the sample mean if the

Using the information in the previous problem, what is the Normal Model?Use the notation N(

Scores on the mathematics part of the SAT exam in a recent year followed a normal distribution with mean 515 and standard deviation 114. You choose an SRS of 100 students and calculate mean SAT Math score. Match up the following for this situation.

Use the information in the previous question. What is the probability of getting a sample of 100 registered voters with more than 65% democrats?Keep all decimals.

Using the information above, suppose an actual sample of 100 of the registered voters actually resulted in 65% democrats. Would you have convincing evidence that the estimated 52% democrat voters was incorrect? Explain.

Use the information from the previous question:What is the shape of the population and the sampling distribution of x-bar ? Justify.

Match the correct notation with the definition.

A study of voting chose 663 registered voters at random shortly after an election. Of these, 72% said they had voted in the election. Election records show that only 56% of registered voters voted in the election. Match up the following statements about these percentages?

A polling organization wants to estimate the proportion of voters who favor a new law banning smoking in public buildings. The organization decides to increase the size of its random sample of voters from about 1500 people to about 4000 people right before an election. The effect of this is to

The central limit theorem is important in statistics because it allows us to use the normal distribution to find probabilities involving the sample mean if the

Using the information in the previous problem, what is the Normal Model?Use the notation N(

Scores on the mathematics part of the SAT exam in a recent year followed a normal distribution with mean 515 and standard deviation 114. You choose an SRS of 100 students and calculate mean SAT Math score. Match up the following for this situation.

Use the information in the previous question. What is the probability of getting a sample of 100 registered voters with more than 65% democrats?Keep all decimals.

Using the information above, suppose an actual sample of 100 of the registered voters actually resulted in 65% democrats. Would you have convincing evidence that the estimated 52% democrat voters was incorrect? Explain.

Use the information from the previous question:What is the shape of the population and the sampling distribution of x-bar ? Justify.

Match the correct notation with the definition.

A study of voting chose 663 registered voters at random shortly after an election. Of these, 72% said they had voted in the election. Election records show that only 56% of registered voters voted in the election.
Match up the following statements about these percentages?

A polling organization wants to estimate the proportion of voters who favor a new law banning smoking in public buildings.
The organization decides to increase the size of its random sample of voters from about 1500 people to about 4000 people right before an election.
The effect of this is to

Using the information in the previous problem, what is the Normal Model?
Use the notation N(

Scores on the mathematics part of the SAT exam in a recent year followed a normal distribution with mean 515 and standard deviation 114.
You choose an SRS of 100 students and calculate mean SAT Math score.
Match up the following for this situation.

Use the information in the previous question.
What is the probability of getting a sample of 100 registered voters with more than 65% democrats?
Keep all decimals.

Use the information from the previous question:
What is the shape of the population and the sampling distribution of x-bar ? Justify.

A study of voting chose 663 registered voters at random shortly after an election. Of these, 72% said they had voted in the election. Election records show that only 56% of registered voters voted in the election.
Match up the following statements about these percentages?

A polling organization wants to estimate the proportion of voters who favor a new law banning smoking in public buildings.
The organization decides to increase the size of its random sample of voters from about 1500 people to about 4000 people right before an election.
The effect of this is to

Using the information in the previous problem, what is the Normal Model?
Use the notation N(

Scores on the mathematics part of the SAT exam in a recent year followed a normal distribution with mean 515 and standard deviation 114.
You choose an SRS of 100 students and calculate mean SAT Math score.
Match up the following for this situation.

Use the information in the previous question.
What is the probability of getting a sample of 100 registered voters with more than 65% democrats?
Keep all decimals.

Use the information from the previous question:
What is the shape of the population and the sampling distribution of x-bar ? Justify.