Construct the indicated confidence interval for the difference between population means. Assume that the two samples are independent simple random samples selected from normally distributed populations. Do not assume that the population standard deviations are equal. A researcher was interested in compairing the resting pulse rates of people who exercise regularly and the pulse rates of people who do not exercise regularly. She obtained independent simple random samples of 16 people who do not exercise regularly and 12 people who do exercise regularly. The resting pulse rates (in beats per minute) were recorded and the summary statistics are as follows. Construct a 95% confidence interval for mu1 - mu2, the difference between the mean pulse rate of people who do not exercise regularly and the mean pulse rate of people who exercise regularly.

H1:

> 26.1

n = 9

= 0.01

Selected Answer:

20.090

Question 11

5 out of 5 points

Find the number of successes x suggested by the given statement.

A computer manufacturer randomly selects 2850 of its computers for quality assurance and

finds that 1.79% of these computers are found to be defective.

Selected Answer:

51

Question 12

5 out of 5 points

Assume that you plan to use a significance level of alpha = 0.05 to test the claim that p1 = p2,

Use the given sample sizes andnumbers of successes to find the pooled estimate

Round

your answer to the nearest thousandth.

n1 = 570;n2 = 1992

x1 = 143;x2 = 550

Selected Answer:

0.270

Question 13

5 out of 5 points

Assume that you plan to use a significance level of alpha = 0.05 to test the claim that p1 = p2.

Use the given sample sizes and numbers of successes to find the z test statistic for the

hypothesis test.

A report on the nightly news broadcast stated that 10 out of 108 households with pet dogs

were burglarized and 20 out of 208 without pet dogs were burglarized.

Selected Answer:

z = -0.102

Question 14

5 out of 5 points

Solve the problem.

The table shows the number of smokers in a random sample of 500 adults aged 20-24 and the

number of smokers in a random sample of 450 adults aged 25-29. Assume that you plan to

use a significance level of alpha = 0.10 to test the claim that

Find the critical value(s)

for this hypothesis test. Do the data provide sufficient evidence that the proportion of smokers

in the 20-24 age group is different from the proportion of smokers in the 25-29 age group?

Selected Answer:

z = 1.645; yes

Question 15

5 out of 5 points

Assume that you plan to use a significance level of alpha = 0.05 to test the claim that p1 = p2.

Use the given sample sizes and numbers of successes to find the P-value for the hypothesis

test.

n1 = 50;n2 = 75

x1 = 20;x2 = 15

Selected Answer:

0.0146

Question 16

5 out of 5 points

Construct the indicated confidence interval for the difference between population proportions

p1 - p2. Assume that the samples are independent and that they have been randomly selected.

x1 = 61, n1 = 105 and x2 = 82, n2 = 120; Construct a 98% confidence interval for the

difference between population proportions p1 - p2.

Selected Answer:

-0.252 < p1 - p2 < 0.047

Question 17

0 out of 5 points

Construct the indicated confidence interval for the difference between the two population

means. Assume that the two samples are independent simple random samples selected from

normally distributed populations. Do not assume that the population standard deviations are

equal.

A researcher was interested in comparing the resting pulse rates of people who exercise

regularly and the pulse rates of people who do not exercise regularly. She obtained

independent simple random samples of 16 people who do not exercise regularly and 12

people who do exercise regularly. The resting pulse rates (in beats per minute) were recorded

and the summary statistics are as follows.

Construct a 95% confidence interval for mu1 - mu2, the difference between the mean pulse

rate of people who do not exercise regularly and the mean pulse rate of people who exercise

regularly.

A). -3.22 beats/min < mu1 - mu2 < 11.62 beats/min

B). -3.55 beats/min < mu1 - mu2 < 11.95 beats/min

C). -3.74 beats/min < mu1 - mu2 < 12.14 beats/min

D). -4.12 beats/min < mu1 - mu2 < 14.72 beats/min