Badm

• Question 1

10 out of 10 points

A random sample of 144 observations has a mean of 20, a median of 21, and a mode of 22. The population standard deviation is known to equal 4.8. The 95.44% confidence interval for the population mean is

Selected Answer: D.

19.2 to 20.8

Correct Answer: D.

19.2 to 20.8

• Question 2

10 out of 10 points

The manager of a grocery store has taken a random sample of 100 customers. The average length of time it took these 100 customers to check out was 3.0 minutes. It is known that the population standard deviation of the checkout time is one minute. The 95% confidence interval for the average checkout time of all customers is

Selected Answer: C.

2.804 to 3.196

Correct Answer: C.

2.804 to 3.196

• Question 3

5 out of 5 points

In order to estimate the average time spent on the computer terminals per student at a local university, data were collected from a sample of 81 business students over a one-week period. Assume the population standard deviation is 1.2 hours. With a 0.95 probability, the margin of error is approximately

Selected Answer: a.

0.26

Correct Answer: a.

0.26

• Question 4

10 out of 10 points

A sample of 26 elements from a normally distributed population is selected. The sample mean is 10 with a standard deviation of 4. The 95% confidence interval for the population mean is

Selected Answer: c.

8.38 to 11.62

Correct Answer: c.

8.38 to 11.62

• Question 5

0 out of 15 points

The following random sample was collected. Assume the population is normally distributed.

9 7 6 10

The 95% confidence interval for μ is

Selected Answer: d.

5.23 to 8.76

Correct Answer: b.

5.09 to 10.90

• Question 6

0 out of 10 points

In a random sample of 500 college students, 23% say that they read or watch the news every day. Develop a 90% confidence interval for the...