To evaluate the effect of a treatment, a sample of n = 8 is obtained from a population with a mean of µ = 40, and the treatment is administered to the individuals in the sample. After treatment, the sample mean is found to be µ = 35.
a. If the sample variance is s2 = 32, are the data sufficient to conclude that the treatment has a significant effect using a two-tailed test with a = .05?
b. If the sample variance is s2 = 72, are the data sufficient to conclude that the treatment has a significant effect using a two-tailed test with a = .05?
c. Comparing your answer for parts a and b, how does the variability of the scores in the sample influence the outcome of a hypothesis test?