Assume that we want to construct a confidence interval. Do one of the followingas appropriate: (a) find the critical value t a/2 , (b) find the critical value z a/2 ,or(c) state that neither the normal distribution nor the t distribution applies . Here are summary statistics for randomly selected weights of newborn girls. n = 170 , x = 29.5hg, s = 6.6hg . The confidence level is 99%. Select the correct choice below and , if necessary , fill in the answer box to complete your choice