Question: A random sample of n=36 scores is selected from a normal population with a u=60. After a treatment is administered to the individuals in the sample, the sample mean is found to be M=52.

a. If the population standard deviation is o=18, is the sample mean sufficient effect? Use a two-tailed test with o=.05.

b. If the population standard deviation is o=30, is the sample mean sufficient to conclude that the treatment has a significant effect? Use a two-tailed test with o=.05.

c. Comparing your answers for parts a and b, explain how the magnitude of the standard deviation influences the outcome of a hypothesis test.