To evaluate the effect of a treatment, a sample of n = 8 is obtained from a population with a mean of 50, and the treatment is administered to the in- dividuals in the sample. After treatment, the sample mean is found to be M 55. 1 a. Assuming that the sample variance is s = 32, use a two-tailed hypothesis test with a = .05 to determine whether the treatment effect is significant and com- pute both Cohen's d and r' to measure effect size.