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=290, x=31.5 hg, s=7.9 hg. The confidence level is 90%.

Select the correct choice belowand, ifnecessary, fill in the answer box to complete your choice.

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.