Assume that we want to construct a confidence interval. Do one of the following, as appropriate: (a) find the critical Value ta/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=289, X = 28.1 hg, s = 7.8 hg. The confidence
level is 95%
Select the correct choice below and, if necessary, fill in the answer box to complete your choice.