# Hypothesis Testing on Three Scenarios

1. An aircraft manufacturer is attempting to determine if the average leg length of the adult male has changed from 44". A sample of 81 men was selected randomly and the average length was found to be 45.5", with a standard deviation of 5.5". Test the null hypothesis that the average leg length of the adult male is 44", at a = 0.05.

2. If Z = 1.96, s = 3, and E = 1, determine the correct sample size.

a. 150

b. 35

c. 6

d. 12

3. A marketing manager wants to determine if the advertising spending per month of his competitors is equal or not. Data over the last six months reveals the following figures (in thousands of dollars). Feel free to use Excel to check your work.

A B C

11 9 12

17 12 23

27 27 28

35 45 27

43 54 39

38 32 41

A. Calculate the SSE for these observations;

1. 196

2. 783.50

3. 2942

4. 2934

5. None of the above.

B. Compute the SST for these observations (answers below are rounded)

1. 4

2. 8

3. 2934

4. 16

5. None of the above.

C. Calculate the F-ratio for the ANOVA based on these observations;

1. 0.05

2. 3.68

3. 0.021

4. 0.010

5. None of the above.

D. Find the F-value from the table in the back of the book to test the hypothesis that there is no difference in the average spending among these companies at α= 0.05

1. 3.68

2. 19.43

3. 0.02

4. 3.29

5. None of the above.

E. What is your null hypothesis? What is your alternative hypothesis? What your decision about the null hypothesis?

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#### Solution Summary

This solution states the null and alternative hypothesis for each scenario, it compares the test statistic to the p-value and makes a decision to accept or reject the null hypothesis. All steps are shown on an Excel file.