A researcher is investigating the effectiveness of a new study-skills training program for

elementary school children. A sample of n = 64 third-grade children is selected 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 = 150 and a standard deviation of = 22. The

mean for the sample is M = 156.

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 hypotheses (H₀ and H₁) for the two-tailed test.

d. Calculate the test statistic (z-score) for the sample.