Question

3. A researcher is preparing a new study and determines that she will be conducting a single sample t-test, and her effect size will be .50.

a) How many total participants does she need to reach a power of .85 with an alpha = .05?

b) Interpret your answer to Question 2a. In other words, what does a power equal to .85 mean in the context of testing a hypothesis?

Answer 1

Single sample t test is useful whether the sample mean is statistically different from a known or hypothezied population mean. It is a parametric test and also known as One sample t test.

a. Your sample size computed is 38( calculations based on effeect size 0.50, power 0.85 and alpha 0.05)

b. Power means the probability of accepting alternaive hypothsis when it is true. In this context it means 85%

means we have a chance of accepting alternative hypothesis when it is true.

Thanks