7

Assume that we want to construct a confidence interval. Do one of thefollowing, asappropriate: (a) find the critical value t/2, (b) find the critical value z/2, or(c) state that neither the normal distribution nor the t distribution applies.

Here are summary statistics for randomly selected weights of newborngirls: n=161, x=28.6 hg, s=6.3 hg. The confidence level is 99%.

Select the correct choice belowand, ifnecessary, fill in the answer box

A.

t/2=

(Round to two decimal places asneeded.)

B.

z/2=

(Round to two decimal places asneeded.)

C.

Neither the normal distribution nor the t distribution applies