A. Identify the critical value in each of the following. Indicate the rejection region and sketch the curve. One point will be given for every correct answer while two points will be given for every sketch. 1. Right-tailed test; = 0.01; df = 22 2. Two-tailed test; = 0.10; n = 16 3. Left-tailed test; = 0.05; n = 20

B. State the null and alternative hypotheses for each statement.

1. The average age of the students in Grade 11 at least 14 years.

2. In the fast food example from the start of this chapter, researchers want to test whether the average number of fast food meals eaten per week by modern families is larger than it was in the 1990s, when it was 3.5.

3. The school principal wants to test if it is true what teachers say - that high school juniors use the computer an average 3.2 hours a day. What are our null and alternative hypotheses?

C. Determine if one-tailed or two-tailed test fits the given alternative hypothesis. 1. The mean weight of Grade 10 students is at most 50 inches. 2. The standard deviation of their scores in monthly test is not equal to 75%. 3. The standard deviation of IQ scores of actors is less than 20. 4. The proportion of drivers who admit to running red lights is greater than 0.5. 5. The mean height of professional basketball players is at least 5 ft.