Question: A sample of n = 25 individuals is randomly selected from a population with a mean of μ = 65, and a treatment is administered to the individuals in the sample. After treatment, the sample mean is found to be M = 70.

a. If the sample standard deviation is s = 10, are the data sufficient to conclude that the treatment has a significant effect using a two-tailed test with α = .05?

b. If the sample standard deviation is s = 20, are the data sufficient to conclude that the treatment has a significant effect using a two-tailed test with α = .05?