1. Students applying to graduate schools in many disciplines are required to take the Graduate Record Examination (GRE). An ambitious undergraduate student creates a study program that she believes will greatly increase students' GRE scores, relative to the general population. She recruits a sample of 100 students believed to be representative of the larger undergraduate student population and puts them through the study program. Afterwards, they complete the GRE and receive a mean score of M = 720. The population of GRE scores is normally distributed with a mean of = 1100 and a standard deviation of = 200.

a) What are the null and alternative hypotheses for this research study?

b)An analysis conducted to determine whether the GRE scores for a sample of students who completed this program were higher than the general population yielded z = 2.24, p= .025. If the researcher usesa = .01 as their criteria for identifying a significant difference or effect, what decision would they make about the null hypothesis and why?

c) What would you conclude based on the results of the analysis conducted in question b? (i.e., relate your decision about the null hypothesis back to the research hypothesis)

d) What is the effect size for this research scenario (show your work)? Based on its value, what kind of impact did the study program have on students' GRE performance? Briefly explain your answer.

e) Would the decision about the null hypothesis from question b change if the researcher useda = .05 for the test? Why or why not?