Question 1 (1 point)

Question 1 options:

The population standard deviation for the height of college football players is 3.3 inches. If we want to estimate a 90% confidence interval for the population mean height of these players with a 0.7 margin of error, how many randomly selected players must be surveyed? (Round up your answer to nearest whole number) Answer:

Question 2 (1 point)

Question 2 options:

The population standard deviation for the height of college hockey players is 3.4 inches. If we want to estimate 90% confidence interval for the population mean height of these players with a 0.6 margin of error, how many randomly selected players must be surveyed? (Round up your answer to nearest whole number) Answer:

Question 3 (1 point)

Question 3 options:

The population standard deviation for the height of college basketball players is 3.4 inches. If we want to estimate 95% confidence interval for the population mean height of these players with a 0.5 margin of error, how many randomly selected players must be surveyed? (Round up your answer to nearest whole number) Answer:

Question 4 (1 point)

Question 4 options:

There is no prior information about the proportion of Americans who support gun control in 2018. If we want to estimate 95% confidence interval for the true proportion of Americans who support gun control in 2018 with a 0.36 margin of error, how many randomly selected Americans must be surveyed? Answer: (Round up your answer to nearest whole number)

Question 5 (1 point)

Question 5 options:

The population standard deviation for the height of college basketball players is 3 inches. If we want to estimate a 99% confidence interval for the population mean height of these players with a 0.5 margin of error, how many randomly selected players must be surveyed? (Round up your answer to nearest whole number) Answer:

Question 6 (1 point)

Question 6 options:

There is no prior information about the proportion of Americans who support Medicare-for-all in 2019. If we want to estimate 95% confidence interval for the true proportion of Americans who support Medicare-for-all in 2019 with a 0.3 margin of error, how many randomly selected Americans must be surveyed? Answer: (Round up your answer to nearest whole number)

Question 7 (1 point)

Question 7 options:

A researcher would like to estimate the proportion of all children that have been diagnosed with Autism Spectrum Disorder (ASD) in their county. They are using 95% confidence level and the CDC national estimate that 1 in 68 0.0147 children are diagnosed with ASD. What sample size should the researcher use to get a margin of error to be within 2%? Round up to the nearest integer. Answer

Question 8 (1 point)

Question 8 options:

A teacher wanted to estimate the proportion of students who take notes in her class. She used data from a random sample of size n = 82 and found that 50 of them took notes. The 99% confidence interval for the proportion of student that take notes is:

< p <

. Round answers to 3 decimal places.

Question 9 (1 point)

Question 9 options:

In a random sample of 80 people, 52 consider themselves as baseball fans. Compute a 95% confidence interval for the true proportion of people consider themselves as baseball fans and fill in the blanks appropriately. We are 95% confident that the true proportion of people consider themselves as baseball fans is between

and

. (round to 3 decimal places)

Question 10 (1 point)

Question 10 options:

Suppose a marketing company wants to determine the current proportion of customers who click on ads on their smartphones. It was estimated that the current proportion of customers who click on ads on their smartphones is 0.42 based on a random sample of 100 customers. Compute a 92% confidence interval for the true proportion of customers who click on ads on their smartphones and fill in the blanks appropriately.

< p <

(round to 3 decimal places)

Question 11 (1 point)

From a sample of 500 items, 30 were found to be defective. The point estimate of the population proportion defective will be:

Question 11 options:

0.06

0.60

0.94

30

Question 12 (1 point)

The percent defective for parts produced by a manufacturing process is targeted at 4%. The process is monitored daily by taking samples of sizes n = 160 units. Suppose that today's sample contains 14 defectives. How many units would have to be sampled to be 95% confident that you can estimate the fraction of defective parts within 2% (using the information from today's sample--that is using the result that p^=0.0875 Place your answer, as a whole number, in the blank. For example 567 would be a legitimate entry.

___

___

Question 12 options:

Question 13 (1 point)

You are told that a random sample of 150 people from Iowa has been given cholesterol tests, and 60 of these people had levels over the "safe" count of 200. Construct a 95% confidence interval for the population proportion of people in Iowa with cholesterol levels over 200.

Place your LOWER limit, rounded to 3 decimal places, in the first blank___. For example, 0.678 would be a legitimate entry. Place your UPPER limit, rounded to 3 decimal places, in the second blank ___. For example, 0.789 would be a legitimate entry.

Make sure you include the 0 before the decimal.

___

Question 13 options:

Blank # 1

Blank # 2

Question 14 (1 point)

Senior management of a consulting services firm is concerned about a growing decline in the firm's weekly number of billable hours. The firm expects each professional employee to spend at least 40 hours per week on work. In an effort to understand this problem better, management would like to estimate the standard deviation of the number of hours their employees spend on work-related activities in a typical week. Rather than reviewing the records of all the firm's full-time employees, the management randomly selected a sample of size 51 from the available frame. The sample mean and sample standard deviations were 48.5 and 7.5 hours, respectively. Construct a 88% confidence interval for the mean of the number of hours this firm's employees spend on work-related activities in a typical week. Place your LOWER limit, in hours, rounded to 1 decimal place, in the first blank. For example, 6.7 would be a legitimate entry.___ Place your UPPER limit, in hours, rounded to 1 decimal place, in the second blank. For example, 12.3 would be a legitimate entry.___

___

Question 14 options:

Blank # 1

Blank # 2

Question 15 (1 point)

Suppose you compute a confidence interval with a sample size of 25. What will happen to the confidence interval if the sample size increases to 50?

Question 15 options:

Get larger

Nothing

Get smaller

Question 16 (1 point)

The personnel department of a large corporation wants to estimate the family dental expenses of its employees to determine the feasibility of providing a dental insurance plan. A random sample of 12 employees reveals the following family dental expenses (in dollars).

See Attached Excel for Data.

dental expense data.xlsx Construct a 93% confidence interval estimate for the mean of family dental expenses for all employees of this corporation. Place your LOWER limit, in dollars rounded to 1 decimal place, in the first blank. Do not use a dollar sign, a comma, or any other stray mark. For example, 98.4 would be a legitimate entry.___ Place your UPPER limit, in dollars rounded to 1 decimal place, in the second blank. Do not use a dollar sign, a comma, or any other stray mark. For example, 567.8 would be a legitimate entry.___

___

Question 16 options:

Blank # 1

Blank # 2

Question 17 (1 point)

In a certain town, a random sample of executives have the following personal incomes (in thousands); Assume the population of incomes is normally distributed. Find the 95% confidence interval for the mean income.

See Attached Excel for Data.

income data.xlsx

Question 17 options:

32.180 < < 55.543

35.132 < < 50.868

40.840 < < 45.160

39.419 < < 46.581

35.862 < < 50.138

Question 18 (1 point)

A researcher finds a 95% confidence interval for the average commute time in minutes using public transit is (15.75, 28.25). What is the correct interpretation of this interval?

Question 18 options:

There is a 95% chance commute time in minutes using public transit is between 15.75 and 28.25 minutes.

We are 95% confident that all commute time in minutes for the population using public transit is between 15.75 and 28.25 minutes.

We are 95% confident that the interval between 15.75 and 28.25 minutes contains the population mean commute time in minutes using public transportation.

We are 95% confident that the interval between 15.75 and 28.25 minutes contains the sample mean commute time in minutes using public transportation.

Question 19 (1 point)

A random sample of college football players had an average height of 66.35 inches. Based on this sample, (65.6, 67.1) found to be a 90% confidence interval for the population mean height of college football players. Select the correct answer to interpret this interval.

Question 19 options:

	We are 90% confident that the population mean height of college football players is between 65.6 and 67.1 inches.
	There is a 90% chance that the population mean height of college football players is between 65.6 and 67.1 inches.
	We are 90% confident that the population mean height of college football palyers is 66.35 inches.
	A 90% of college football players have height between 65.6 and 67.1 inches. Question 20 (1 point) Question 20 options: A randomly selected sample of college basketball players has the following heights in inches. See Attached Excel for Data. height data.xlsx Compute a 93% confidence interval for the population mean height of college basketball players based on this sample and fill in the blanks appropriately. < < (round to 3 decimal places) Submit Quiz0 of 20 questions saved