Question 1041477
Using a calculator, 
mean = xbar = 241.75
standard deviation = s = 86.6


lower bound = xbar - s = 241.75-86.6 = 155.15 which rounds to 155.2


upper bound = xbar + s = 241.75+86.6 = 328.35 which rounds to 328.4


So the answer is choice C