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,

(c) state that neither the normal distribution nor the t distribution applies.

Here are summary statistics for randomly selected weights of newborngirls: n=214, x=33.5 hg, s=7.2 hg. The confidence level is 90%.