Hypothesis Testing Worksheet

Part 1: Each of the following situations requires a significance test about a population mean. State the appropriate null hypothesis (H0) and alternative hypothesis (H1) in each case:

1. Census Bureau data shows that the mean household income in the area served by a shopping mall is $72,500 per year. A market research firm questions shoppers at the mall to find out whether the mean household income of mall shoppers is higher than that of the general population

• H₀:
• H_1:

2. Last year, your company's service technicians took an average of 1.8 hours to respond to trouble calls from business customers who had purchased service contracts. Does this year's data show a different average response time?

• H₀:
• H_1:

Part 2: A recent report claims that among the general adult population in the United States is significantly larger than in European countries. Data indicates that the average weight of Americans is 180 pounds with a standard deviation of 20 pounds. In contrast, a sample of 25 Europeans had a mean weight of 160. Based on our sample, does the data support this report? Use a 5% level of significance. 1. State the appropriate null hypothesis (H0) and alternative hypothesis (H1)

• H₀:
• H_1:

2. Is this a right, left or two-tailed test?

3. Use you calculator to find the calculated value of z and the associated P Value. State these below (show your work):

4. Do we reject or not reject the null hypothesis? Why or why not? Include in your discussion the calculated value of z and the p-value.

Part 3: The Survey of Study Habits and Attitudes (SSHA) is a psychological test that measures study habits of students. The mean score for the population of U.S. college students is about 115, and the standard deviation is about 30. A teacher who suspects that older students have better attitudes toward school gives the SSHA to 20 students who are at least 30 years of age who scored an average of 120.

1. State the appropriate null hypothesis (H0) and alternative hypothesis (H1)

• H₀:
• H_1:

2. Is this a right, left or two-tailed test?

3. Use you calculator to find the calculated value of z and the associated P Value. State these below (show your work):

4. Do we reject or not reject the null hypothesis? Why or why not? Include in your discussion the calculated value of z and the p-value.

Part 4: In the United States, the population mean life span is 77 years with a standard deviation of 10 years. A researcher was curious as to whether those who live in Hawaii have the same average; he took a sample of 36 obituaries from the Honolulu Times and found they had lived an average of 81 years. Does this information indicate that the population mean life span for Honolulu residents is significantly different than 77 years? Use a 5% level of significance.

1. State the appropriate null hypothesis (H0) and alternative hypothesis (H1)

• H₀:
• H_1:

2. Is this a right, left or two-tailed test?

3. Calculate the value of z and the associated p-value. State these below (show your work): 4. Do we reject or not reject the null hypothesis? Why or why not? Include in your discussion the calculated value of z and the P Value.