Assume that we want to construct a confidence interval. Do one of the following, as appropriate: (a) find the critical value ta/2. (b) find the critical value Za/2. or (c) state that neither the normal distribution nor the t distribution applies. The confidence level is 90%, is not known, and the histogram of 58 player salaries (in thousands of dollars) of football players on a team is as shown. Select the correct choice below and, if necessary, fill in the answer box to complete your choice. OA. 1a/2 (Round to two decimal places as needed.) OB. Za/2 (Round to two decimal places as needed.) OC. Neither the normal distribution nor the t distribution applies. Frequency 40- 30- 20 10- 0- 0 4000 8000 12000 16000 20000 Salary (thousands of dollars)