In the population of typical college students, = 75 on a statistics final exam (x = 6.4). For 25 students who studied statistics using a new technique, = 72.1. Using two tails of the sampling distribution and the .05 criterion: (a) What is the critical value? (b) Is this sample in the region of rejection? How do you know? (c) Should we conclude that the sample represents the population of typical students? (d) Why?

2. In a population, = 100 and x = 25. A sample (N=150) has = 102. Using two tails of the sampling distribution and the .05 criterion: (a) What is the critical value? (b) Is this sample in the region of rejection? How do you know? (c) What does this indicate about the likelihood of this sample occurring in this population? (d) What should we conclude about the sample? 13

3. We obtain a = 46.8 (N= 15) which may represent the population where = 50 ( x = 11). Using the criterion of .05 and the lower tail of the sampling distribution: (a) What is our critical value? (b) Is this sample in the region of rejection? How do you know? (c) What should we conclude about the sample? (d) Why?