A random sample is selected from a normal population with a mean of = 30 and a standard deviation of = 8. After

A random sample is selected from a normal population with a mean of μ = 30 and a standard deviation of σ = 8.

After a treatment is administered to the individuals in the sample, the sample mean is found to be M = 33.

a. If the sample consists of n = 16 scores, is the sample mean sufficient to conclude that the treatment has a significant effect? Use a two-tailed test with α = .05.

b. If the sample consists of n = 64 scores, is the sample mean sufficient to conclude that the treatment has a significant effect? Use a two-tailed test with α = .05.

c. Comparing your answers for parts a and

b, explain how the size of the sample influences the outcome of a hypothesis test.