Q1.

A coin-operated drink machine was designed to discharge a mean of 9 fluid ounces of coffee per cup. In a test of the machine, the discharge amounts in 13 randomly chosen cups of coffee from the machine were recorded. The sample mean and sample standard deviation were 8.95 fluid ounces and 0.29 fluid ounces, respectively.

If we assume that the discharge amounts are approximately normally distributed, is there enough evidence, to conclude that the population mean discharge, , differs from 9 fluid ounces? Use the 0.05 level of significance.

Perform a two-tailed test. Then complete the parts below.

Carry your intermediate computations to three or more decimal places.

(a)	State the null hypothesis H0 and the alternative hypothesis H1.
H0:
H1:
(b)	Determine the type of test statistic to use.
	(Choose one - Z, t, Chi-square, F)
(c)	Find the value of the test statistic. (Round to three or more decimal places.)
(d)	Find the p-value. (Round to three or more decimal places.)
(e)	Can we conclude that the mean discharge differs from 9 fluid ounces?
Yes No

Q2.

The proportion p of residents in a community who recycle has traditionally been 70%. A policy maker claims that the proportion is less than 70% now that one of the recycling centers has been relocated. If 146 out of a random sample of 220 residents in the community said they recycle, is there enough evidence to support the policy maker's claim at the 0.05 level of significance? Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places.

(a)	State the null hypothesis H0 and the alternative hypothesis H1.
H0:
H1:
(b)	Determine the type of test statistic to use.
	(Choose one - Z, t, Chi-square, F)
(c)	Find the value of the test statistic. (Round to three or more decimal places.)
(d)	Find the p-value. (Round to three or more decimal places.)
(e)	Is there enough evidence to support the policy maker's claim that the proportion of residents who recycle is less than 70%?
Yes No

Q3.

A marriage counselor has traditionally seen that the proportion p of all married couples for whom her communication program can prevent divorce is 80%. After making some recent changes, the marriage counselor now claims that her program can prevent divorce in more than 80% of married couples. In a random sample of 220 married couples who completed her program, 189 of them stayed together. Based on this sample, is there enough evidence to support the marriage counselor's claim at the 0.10 level of significance? Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places.

(a)	State the null hypothesis H0 and the alternative hypothesis H1.
H0:
H1:
(b)	Determine the type of test statistic to use.
	(Choose one- Z, t, Chi-square, F )
(c)	Find the value of the test statistic. (Round to three or more decimal places.)
(d)	Find the p-value. (Round to three or more decimal places.)
(e)	Is there enough evidence to support the marriage counselor's claim that the proportion of married couples for whom her program can prevent divorce is more than 80%?
Yes No

Q4.

A decade-old study found that the proportion, p, of high school seniors who believed that "getting rich" was an important personal goal was 75%. A researcher decides to test whether or not that percentage still stands. He finds that, among the 230 high school seniors in his random sample, 164 believe that "getting rich" is an important goal. Can he conclude, at the 0.01 level of significance, that the proportion has indeed changed? Perform a two-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places.

(a)	State the null hypothesis H0 and the alternative hypothesis H1.
H0:
H1:
(b)	Determine the type of test statistic to use.
	(Choose one- Z, t, Chi-square, F )
(c)	Find the value of the test statistic. (Round to three or more decimal places.)
(d)	Find the p-value. (Round to three or more decimal places.)
(e)	Can we conclude that the proportion of high school seniors who believe that "getting rich" is an important goal has changed?
Yes No