A
random sample is selected from a normal population with a mean of μ
= 20 and a standard deviation of σ =5 10. After a treatment is
administered to the individuals in the sample, the sample mean is
found to be M = 25. If the sample consists of n = 25 scores, is the
sample mean sufficient to conclude that the treatment has a
significant effect? Use a two-tailed test with alpha =
.05.