Consider the following two confidence intervals for u from a normal sample. (113.8, 116.2), (113.5, 116.5) (a) What is the value of the sample mean used to construct these CIs? (b) The confidence level for one of the intervals is 95% and for the other it is 99%. Which is which, and how can you tell? (c) Consider: 20.025 = 2 and zo.005 = 2.5. We know that the sample size n = 100. Based on b), calculate the standard deviation.