The arithmetic mean and standard deviation of a certain normal distribution are 16.2 and 2.3, respectively. What value is exactly 2 standard deviations less than the mean?	Choose the correct choice:  A) 10.5  B) 11  C) 11.6  D) 12  E) 12.5

Rationale: "mean = 16.2 two standard deviations is 2.3 + 2.3 = 4.6 there could be two calues for this . mean + two standard deviations = 20.8 mean - two standard deviations = 11.6 answer choice has 11.6 and so c is the answer ."
Answer: C