1. Explain the difference between testing a single mean, testing the difference between two means from an "independent sample" and testing mean differences from a "dependent sample".
2. Choose a variable. You will be comparing the means of two groups to each other. Your sample will consist of 12 subjects in each group. You may collect data or create data.
a. Write a brief statement of purpose of the study
b. Define the two groups
c. State the hypotheses for the study
d. Select an alpha value
e. Show the raw data
f. Decide which statistical test is appropriate and compute the test statistic (independent samples t-test or dependent samples t-test). Why is the test appropriate?
g. Find the critical values(s)
h. State the decision
i. Summarize the results
3. What does increasing your level of confidence do to the interval estimate?
4. From your t distribution table and for df = 25, note whether the following t scores are significant at the alpha = .05 level for a one-tailed test; a two-tailed test.
a. t = -1.316
b. t = +.316
c. t = -2.660
d. t = 1.87
5. You are investigating the possible differences between males and females on the importance of communication. Your research hypothesis is that females place more importance on communication than males (higher scores indicate more importance). You have obtained the following data:
Male: sample size = 26, mean = 57.5, s = 9.7
Female: sample size = 24, mean = 65.0, s = 10.2
a. Is this a one-tailed or two-tailed test? Is this a dependent samples or independent samples t-test? What is your null hypothesis? What is your alternate hypothesis?
b. Perform the test at alpha = .05
c. Draw final conclusions