4. In the formula (M-p) / SM, Su is the (Describe in words.) 5. If the mean of a sample is 95, the mean of Population 2 is 75, and the standard deviation of the distribution of means is 5, the f score resulting from a f test for a single sample is_ (Give a number.) 6. Before conducting a t test for dependent means on a set of pretest and posttest scores, the two sets of scores must be combined into one set of scores by figuring