1. Explain thefour steps involved in hypothesis testing and how a statistical decision is made based on computing a test statistic and transforming the sample mean into a z-score (probability score).

2.Using the excerpt below, follow through with the steps of hypothesis testing

"Allthe students at a university tookthe GRE (Graduate Record Examination), astandardized testthat measures graduate readiness.The GRE is scored on a 130-170 scale in each section and the verbal scores were compared.The scoreswerenormally distributed with =140and = 15. Asample of students, n =100,then took a GRE course to improve their test scores.Followingthe course, the average score for this sample is M =155. Is there evidence that theGRE coursehadan effect onthe verbaltest scores?"

3. Thoroughly explain, state, and show the work for the following in orderbased on the research data given above:

• The researchquestion
• The null and alternative hypotheses
• The alpha level and the critical region
• Compute the test statistic using a z-score
• Determine the 95% confidence intervals
• Make a decisionabout the null
• Find the effect size using Cohen's dand state why the effect size should be reported
• Also, include the power of the hypothesis test. Why might the power be used?What factors affect the power?