Question 1 (1 point)

Question 1 options:

The population standard deviation for the height of college basketball players is 2.4 inches. If we want to estimate 97% confidence interval for the population mean height of these players with a 0.35 margin of error, how many randomly selected players must be surveyed? (Round up your answer to nearest whole number, do not include any decimals.) Answer:

Question 2 (1 point)

Question 2 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 97% 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 1.5%? Round up to the nearest integer, do not include decimals. Answer

Question 3 (1 point)

Question 3 options:

The population standard deviation for the height of college football players is 2.7 inches. If we want to estimate a 95% confidence interval for the population mean height of these players with a 0.65 margin of error, how many randomly selected players must be surveyed? (Round up your answer to nearest whole number, do not include any decimals) Answer:

Question 4 (1 point)

Question 4 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 0.175 margin of error, how many randomly selected Americans must be surveyed? Answer: (Round up your answer to nearest whole number, do not include any decimals)

Question 5 (1 point)

Question 5 options:

The population standard deviation for the height of college basketball players is 2.9 inches. If we want to estimate a 99% confidence interval for the population mean height of these players with a 0.45 margin of error, how many randomly selected players must be surveyed? (Round up your answer to nearest whole number, do not include any decimals) Answer:

Question 6 (1 point)

Question 6 options:

The population standard deviation for the height of college basketball players is 3.1 inches. If we want to estimate 99% confidence interval for the population mean height of these players with a 0.58 margin of error, how many randomly selected players must be surveyed? (Round up your answer to nearest whole number, do not include any decimals) Answer:

Question 7 (1 point)

Question 7 options:

There is no prior information about the proportion of Americans who support gun control in 2019. If we want to estimate 97% confidence interval for the true proportion of Americans who support gun control in 2019 with a 0.27 margin of error, how many randomly selected Americans must be surveyed? Answer: (Round up your answer to nearest whole number, do not include any decimals)

Question 8 (1 point)

Question 8 options:

In a random sample of 80 people, 52 consider themselves as baseball fans. Compute a 92% confidence interval for the true proportion of people consider themselves as baseball fans and fill in the blanks appropriately. We are 92% confident that the true proportion of people consider themselves as baseball fans is between

and

. (round to 3 decimal places)

Question 9 (1 point)

Question 9 options:

A random sample found that 30% of 150 Americans were satisfied with the gun control laws in 2018. Compute a 98% confidence interval for the true proportion of Americans who were satisfied with the gun control laws in 2018 Fill in the blanks appropriately. A 98% confidence interval for the true proportion of Americans who were satisfied with the gun control laws in 2018 is (

,

) (round to 3 decimal places)

Question 10 (1 point)

A random sample of 145 people was selected and 13% of them were left handed. Find the 97% confidence interval for the proportion of left-handed people.

Question 10 options:

(0.069, 0.191)

(0.0764, 0.1636)

(0.1125, .1576)

(.13, .87)

(0.0836, 0.1764)

Question 11 (1 point)

Suppose a marketing company computed a 96% confidence interval for the true proportion of customers who click on ads on their smartphones to be (0.59 , 0.71). Select the correct answer to interpret this interval

Question 11 options:

There is a 96% chance that the true proportion of customers who click on ads on their smartphones is between 0.59 and 0.71.

We are 96% confident that the true proportion of customers who click on ads on their smartphones is between 0.59 and 0.71.

We are 96% confident that the true proportion of customers who click on ads on their smartphones is 0.71.

96% of customers click on ads on their smartphones.

Question 12 (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 50 from the available frame. The sample mean and sample standard deviations were 45.5 and 7.5 hours, respectively. Construct a 92% confidence interval for the average 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 12 options:

Blank # 1

Blank # 2

Question 13 (1 point)

A sample of 9 production managers with over 15 years of experience has an average salary of $71,000 and a sample standard deviation of $18,000. Assuming that s = 18,000 is a reasonable estimate for not use a dollar sign, a comma, or any other stray mark. For examples, 34 would be a legitimate entry.___

___

Question 13 options:

Question 14 (1 point)

If a sample has 20 observations and a 95% confidence estimate for

___

Question 14 options:

Question 15 (1 point)

A marketing research consultant hired by Coca-Cola is interested in determining the proportion of customers who favor Coke over other soft drinks. A random sample of 400 consumers was selected from the market under investigation and showed that 53% favored Coca-Cola over other brands. Compute a 95% confidence interval for the true proportion of people who favor Coke. Place your LOWER limit, rounded to 3 decimal places, in the first blank___. For example, 0.345 would be a legitimate entry. Place your UPPER limit in the second blank___. For example, 0.456 would be a legitimate entry. Make sure you include the 0 before the decimal.

___

Question 15 options:

Blank # 1

Blank # 2

Question 16 (1 point)

If everything else stays the same, the margin of error can be reduced by:

Question 16 options:

	Decreasing sample size; Increasing Confidence level
	Decreasing Sample Size; Decreasing confidence level
	Increasing sample size; Decreasing confidence level
	Increasing Sample Size; Increasing Confidence level

Question 19 (1 point)

A random sample of college football players had an average height of 66.5 inches. Based on this sample, (64.2, 67.1) found to be a 95% confidence interval for the population mean height of college football players. Select the correct answer to interpret this interval.

Question 19 options:

We are 95% confident that the population mean height of college football players is between 64.2 and 67.1 inches.

We are 95% confident that the population mean height of college football palyers is 66.5 inches.

A 95% of college football players have height between 64.2 and 67.1 inches.

There is a 95% chance that the population mean height of college football players is between 64.2 and 67.1 inches.

Question 20 (1 point)

A researcher finds a 94% confidence interval for the average commute time in minutes using public transit is (17.86, 27.45). What is the correct interpretation of this interval?

Question 20 options:

	There is a 94% chance commute time in minutes using public transit is between 17.86 and 27.45 minutes.
	We are 94% confident that all commute time in minutes for the population using public transit is between 17.86 and 27.45 minutes.
	We are 94% confident that the interval between 17.86 and 27.45 minutes contains the population mean commute time in minutes using public transportation.
	We are 94% confident that the interval between 17.86 and 27.45 minutes contains the sample mean commute time in minutes using public transportation.