Explain the four steps 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).

Follow through each of the steps of hypothesis testing to answer the question.

All the students at a university took the GRE (Graduate Record Examination), a standardized test that attempts to measure graduate readiness. The GRE is scored on a 130-170 scale in each section, and the verbal scores were compared. The scores were normally distributed with = 140 and = 15. A sample of students, n =100, then took a GRE course to improve their test scores. Following the course, the average score for this sample is M = 155. Is there evidence that the GRE course influenced the verbal test scores?

State the following in order based on the research data given above:

• What is the research question.
• The null and alternative hypotheses.
• The alpha level and the critical region.
• Compute the test statistic using a z-score.
• What are the 95% confidence intervals.
• What is your decision about the null.
• Find the effect size using Cohen's d and state why the effect size should be reported.
• Include the power of the hypothesis test. Why might the power be used? What factors affect power?

Summarize the above information in a table.

In your conclusion, provide a brief explanation of the implications for social change based on your data's results.