1. Find critical values for the following tests:

a. Z - test, = .05, left-tail test

b. Z- test, = .01, two-tail test

c. Z- test, = .1, right-tail test

d. t- test, = .025, sample size = 10, right-tail test

e. t-test, = .2, sample size = 6, two-tail test

f. t-test, = .01, sample size = 23, left-tail test

2. Compute the following test values:

a. Sample mean = 5950, population mean = 5700, population standard deviation = 659, sample size = 36

b. Population mean = 8, sample size = 32, sample mean = 8.2, population standard deviation = .6

c. Sample standard deviation = 1.8, sample mean = 17.7, population mean = 16.3, sample size = 10

d. X1=15, X2=18, 1=2, n1=23, n2=20, o1=2.1, o2=2.3

3. The average production of peanuts in Virginia is 3000 pounds per acre. A new plant food has been developed and tested on 60 plots of land. The mean yield with the new plant food is 3120 pounds per acre, and the population standard deviation is 578 pounds. A study is trying to discover if the average yield has increased. At = .05, answer the following questions

a. State the hypothesis

b. Find the critical value(s)

c. Compute the test value

d. Make the decision to reject or not

e. Summarize the results

4. A consumer organization claims that the mean price of 7.5-cubic-foot refrigerators is greater than $300. Following are prices, in dollars, of a random sample of 7.5-cubic-foot refrigerators. At 1. Find critical values for the following tests:

a. Z - test, = .05, left-tail test

b. Z- test, = .01, two-tail test

c. Z- test, = .1, right-tail test

d. t- test, = .025, sample size = 10, right-tail test

e. t-test, = .2, sample size = 6, two-tail test

f. t-test, = .01, sample size = 23, left-tail test

5. Listed below are home prices in two areas of Pennsylvania. Is there enough evidence to reject the claim that the average cost of a home in both locations is the same? Use .01 level of significance.

Scott Ligonier

Sample mean = $93,430 Sample mean = $98,043

Population standard deviation =$5602 Population standard deviation = $4731

Sample size = 35 Sample size = 40

6. A researcher claims that the mean of the salaries of elementary school teachers is greater than the mean of the salaries of secondary school teachers. The data obtained from her samples are listed below. At = .05, can it be concluded that the mean of elementary salaries are greater than secondary salaries?

Elementary Secondary

Sample mean = $48256 Sample mean = $45633

Sample standard deviation = $3912.40 Sample standard deviation = $5533

Sample size = 26 Sample size = 24