To evaluate the effect of a treatment, a sample of n = 16 is obtained from a population with a mean of µ = 42, and the treatment is administered to the individuals in the sample. After treatment, the sample mean is found to be M = 35.
a. If the sample has a standard deviation of s = 9, are the data sufficient to conclude that the treatment has a significant effect using a two-tailed test with u = .05?
b. If the sample standard deviation is s = 16, are the data sufficient to conclude that the treatment has a significant effect using a two-tailed test with u = .05?