A sample of n = 9 participants is obtained from a population with u = 29, and a treatment is administered to the individuals in the sample. After treatment, the scores for the nine participants are as follows: 23,33, 26, 28, 30, 26, 27, 25, 25.
a. Are the data sufficient to conclude that the treatment has a significant effect? Use a two-tailed test with a = .05.
b. Are the data sufficient to conclude that the treatment significantly decreased scores? Use a one-tailed test with a =.05.