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 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 µ = 150 and a standard deviation of σ = 25. The mean for the sample is M = 158.
a. Identity the independent and the dependent variables for this study.
b. Assuming two-tailed test, state the hypotheses (Ho and H1 ) for the two-tailed test.
c. Using symbols, state the hypotheses (Ho and H1) for the two-tailed test.
d. Sketch the appropriate distribution, and locate the critical regions for α = .05.
e. Calculate the test statistics (z score) for the sample.
f. What decision should be made about the effect of the program?