Suppose you are planning to conduct a study, comparing two independent groups.Participants in one group will be randomly assigned to watch a video that explains how to change the oil in a lawn mower; participants in the other group will be randomly assigned to watch the same video, but an instructor will be present who can demonstrate the procedure and answer questions. After this manipulation, participants in both groups will be tested on how quickly they can change the oil in the lawn mower.

a)Suppose there are 50 participants in each group.If you believe from prior research that d = .2, and you are working with a two-tailed = .05, what is the power of your research design?

b)If your desired power = .80 (and you are still working with a two-tailed = .05), how many participants would you need in each group?