To evaluate the effect of a treatment, a sample of n 5 6 is obtained from a population with a mean of m 5 80, and the treatment is administered to the individuals in the sample. After treatment, the sample mean is found to be M 5 72.

a. If the sample variance is s 2 5 54, are the data sufficient to conclude that the treatment has a significant effect using a two-tailed test with a 5 .05?

b. If the sample variance is s 2 5 150, are the data sufficient to conclude that the treatment has a significant effect using a two-tailed test with a 5 .05?

c. Comparing your answers for parts a and

b, how does the variability of the scores in the sample influence the outcome of a hypothesis test?