Question: A researcher is investigating the effectiveness of a new study-skills training program for elementary school children. A sample of n=25 third-grade children is seleced to participate in the program and each child is given a standardized achievement test at the end of the year. For the regular population of third-grade children, scores, on the test form a normal distribution with a mean of u=150 and a standard deviation of o=25. The mean for the sample is M=158.

a. Identify the independent and the dependent variables for this study.

b. Assuming a two-tailed test, state the null hypothesis in a sentence that includes the independent variable and the dependent variable.

c. Using symbols, state the hypothesis (H0 and H1) for the two-tailed test.

d. Sketch the appropriate distribution, and locate the critical region for o=.05.

e. Calculate the test statistic (z score) for the sample

f. What decision should be made about the null hypothesis, and what decision should be made about the effect of the program?