According to my records, the population of all past PSY 240final percentage scores has a mean (μ) of 85 and standarddeviation (σ) of 7 points. The new class of 36 studentshad a mean (M) final percentage score of 87 points. Iconducted a hypothesis test to see if the new class would havesignificantly differently final percentage scores from thepopulation of past students. I was interested in any type of“difference,” whether it’s an increase or a decrease in finalpercentage score. The significance level for my Z test was set atα= .05.

f. Determine the critical value for Z

1. Compare the obtained Z and critical Z and then make a decisionabout the result of the hypothesis test: Explicitly states “reject”or “fail to reject” the null hypothesis

1. Write 1-2 sentences to conclude the results (you can simplyrestate the accepted hypothesis or explain it in another way)

1. Calculate the raw effect size and the standardized effect sizefor this test.

1. Since the average final percentage score for the new section isnumerically higher than the average final percentage score from theexisting pool of past students, I could also set up a directionalresearch hypothesis. What would the written hypotheses and thenotations be?

1. Using the alpha level of α= .05, determine thecritical Z value for the directionalhypothesis.

l. In this statistical test, how high does the mean finalpercentage score from the new class have to be, at least, to beconsidered “significantly” higher than the pool of past finalpercentage scores?

Hint: In other words, when doesthe calculated Z equal the critical Z? What needs to be the samplemean for that to happen?