1) Find z/2 for 80%,98%, and 99% confidence levels. (It may help to draw the curve and identify /2 in each tail.) 2) Find the following critical values t//2 in the t-table. (Draw the normal curve to identify /2.) a. Sample size 37 for a 90% confidence level. b. Sample size 29 for a 98% confidence level. c. Sample size 9 for an 80% confidence level..