The Essentials of Statistics 3rd Edition by Joseph Healey

Exercise 3

What if the research question in problem 7.2 were changed to "Do seniors cut a significantly greater number of classes"? How would the test change?
(Hint: This wording implies a one-tailed test of significance. How would the research hypothesis change? For the alpha you used in problem 7.2, what would the value of Z(critical) be?)
Problem 7.2: SOC: The students at Littlewood Regional High School cut an average of 3.3 classes per week. A random sample of 117 seniors averages 3.8 cuts per week, with a standard deviation of 0.53. Are seniors significantly different from the student body as a whole? (Hint: The wording of the research question suggests a two-tailed test. This means that the alternative, or research, hypothesis in step 2 will be stated as H 1: µ ? 3.3 and that the critical region will be split between the upper and lower tails of the sampling distribution. See Table 7.1 for values of Z (critical) for various alpha levels.)