A random sample is selected from a normal population with a mean of = 50 and

Question:

A random sample is selected from a normal population with a mean of µ = 50 and a standard deviation of σ = 12. After a treatment is administered to the individuals in the sample, the sample mean is found to be M = 55.

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 = 36 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.