A sample of n = 25 individuals is randomly selected from population with a mean of u = 65, and a specific treatment is
administered to the individuals in the sample. After the
treatment, the sample mean is found to be M = 70.
a.
If the sample standard deviation is s = 10, check if the
treatment has a significant effect using a two-tail test with a =
0.05?
b.
If the sample standard deviation is s = 20, check if the
treatment has a significant effect using a two-tail test with a =
0.05?