Question 1a

A mail-order company has a 12.5% success rate of having people purchase their products. It mails advertisements to 676 people.

What is the probabilitythat less than10% of people will purchase products?

	0.973
	0.159
	0.027
	0.225

Question 1b

According to the National Institutes of Health, 14% of college students said they vaped marijuana in the past 30 days. In a random sample of 250 college students would it beunusualfor 19% to have vaped marijuana in the past 30 days?

Yes

No

Cannot be determined

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Question 1c

What is the relationship between the confidence interval and the margin of error?

Question 1 options:

	None of these
	The confidence interval is twice the margin of error.
	The margin of error is twice the confidence interval.
	The confidence interval is half the width of the margin of error.

Question 2

Which of the following confidence levels will provide the widest intervals?

Question 2 options:

	99%
	90%
	85%
	95%

Question 3

Question 3 options:

A researcher is interested in estimating the how recent college graduates are using their degree in their current profession. In a random sample of 800 recent college graduates 280 report, they are not using degree with their current job. Compute a 90% confidence interval for the true proportion of recent college graduates that are not using their degrees in their jobs. Round to 3 decimal places.

Lower limit =

Upper limit =

Question 4

Write a summary statement for this confidence interval. Be sure to use the context of the problem.

Question 4 options:

Question

A community college would like to estimate the percentage of their students that have children under 18 years old. They randomly select 450 students and ask them about having children and their children's ages. The 90% confidence interval for this situationis (24.5%, 31.5%)

Which statement below correctly summarizes the confidence interval?

Question 5 options:

	There is a 90% chance that the percentage of students at this college that have children (
	We are 90%confident that the percentage of all students at this community collegethat have children (
	Thechance a student will have children (
	We are 90%confident that the percentage of all students at this community college that have children (

Question 6

A pollster wishes to estimate the true proportion of U.S. voters who oppose capital punishment. How many voters should be surveyed in order to be 90% confident that the true proportion is estimated to within 3.5%?

Question 6 options:

Question 7

The confidence interval at the 95% level of confidence for the true population proportion was reported to be (0.284, 0.416). Which of the following is a possible 90% confidence interval from the same sample?

Question 7 options:

	(0.295, 0.405)
	(0.263, 0.437)
	(0.315, 0.425)
	(0.679, 0.821)

.

Question 8

In a random sample of 55 patients in the emergency room, the sample mean waiting time before being seen by a doctor was 26 minutes with a sample standard deviation of 8 minutes. Assume waiting times are approximately normal. Compute a 95% confidence interval for the mean waiting time for all patients to be seen by a doctor.

Question 8 options:

	(23.8, 28.2)
	(24.2, 27.8)
	(25.9, 30.1)
	(22, 30)

Question 9

Write a summary statement for your confidence interval in question #1.

Question 9 options:

Question 10

A random sample ofhighschoolstudents is usedto estimate the mean time all high school students' study forGeometrytests.A95%confidence interval based on this sample is:0.9hours to 2.7hours.

What is the sample mean (

\fTime (hours) 31.3 39.6 39.2 34.8 42.9 33.9 35.2 35.3 35.1 31.3 37.1 39.2 38.1 40.7 29 39.1 29.7 44.2 33.4 32.1 31.6 32.6 32.9 31.5 36.9 41.7 37.3 34.1 36 37.8 34.5 33.6 39.9 39.6 34.4 32.2 34.9 32.6 36.1 36.1 35.2 39.8 35.3 31.5 30 33.3 34.1 38.7 36.5 42.4