Assume that we want to construct a confidence interval. Do one of the following, as appropriate: (a) find the critical value to / 2. (b) find the critical value Za /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 = 274, x=31.7 hg, s =7.6 hg. The confidence level is 95%. Select the correct choice below and, if necessary, fill in the answer box to complete your choice. O A. ta/2= (Round to two decimal places as needed.) O B. Za/2= (Round to two decimal places as needed.) O C. Neither the normal distribution nor the t distribution applies