Assume that we want to construct a confidence interval. Do one of the following, as appropriate: (a) find the critical value t Subscript alpha divided by 2

t/2, (b) find the critical value z Subscript alpha divided by 2

z/2, or (c) state that neither the normal distribution nor the t distribution applies.

The confidence level is 90

90%, sigma

is not known, and the histogram of 61

61 player salaries (in thousands of dollars) of football players on a team is as shown.

0

4000

8000

12000

16000

20000

0

10

20

30

40

Salary(thousandsofdollars)

Frequency

A histogram has a horizontal axis labeled "Salary (thousands of dollars)" from below 0 to above 20000 in increments of 2000 and a vertical axis labeled "Frequency" from 0 to 40 in increments of 10. The histogram contains vertical bars of width 2000, where one vertical bar is centered over each of the horizontal axis tick marks. The heights of the vertical bars are as follows, where the salary is listed first and the height is listed second: 0, 35; 2000, 11; 4000, 3; 6000, 4; 8000, 3; 10000, 3; 12000, 0; 14000, 0; 16000, 1; 18000, 0; 20000, 1.

Select the correct choice below and, if necessary, fill in the answer box to complete your choice.

A.

t Subscript alpha divided by 2

t/2equals

=

nothing

(Round to two decimal places as needed.)

B.

z Subscript alpha divided by 2

z/2equals

=

nothing

(Round to two decimal places as needed.)

C.

Neither the normal distribution nor the t distribution applies.