A random sample of n = 25 scores is selected from a normal population with a mean = 40. After a treatment is administrated to the individuals in the sample, the sample mean is found to be M = 44.
a. If the population standard deviation is 5 is the sample mean sufficient to conclude that the treatment has a significant effect? Use a two tailed test with alpha =.05.
B. If the population standard deviation is 15, is the sample mean sufficient to conclude that the treatment has a significant effect? Use a two tailed test with alpha =.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.