The following MINITAB output presents the results of a power calculation for a test of the difference between two means μ1 ˆ’ μ2.

a. Is the power calculated for a one-tailed or two-tailed test?
b. If the sample sizes were 50 in each group, would the power be less than 0.9, greater than 0.9, or is it impossible to tell from the output? Explain.
c. If the difference were 4, would the power be less than 0.9, greater than 0.9, or is it impossible to tell from the output? Explain.

Transcribed Image Text:

Power and Sample Size 2-Sample t Test Testing mean 1 mean 2 (versus not- Calculating power for me mean 2 difference Alpha 0.05 Assumed standard deviation 5 Sample Size Target Power Actual Power 0.903115 Difference 60 0.9 The sample size is for each group