Answer
The critical values are -1.687 and 1.687. The Rejection region is any value below -1.687 and above 1.687.
Work Step by Step
Using TI-84 calculator:
1. 2nd
2. VARS
3. Scroll down to invT
4. Input alpha given in the problem for the area/2 . In this case area = 0.05
5. Input n -1 for degree of freedom. In this case, df = 37
6. The output is the critical value and the rejection region.