Question: Carbon monoxide (CO) emissions for a certain kind of car vary with mean 2.9 gm/mi and standard deviation 0.4 gm/mi. A company has 130 cars in its fleet. Let y (y with line above it) represent the mean CO level for the company’s fleet. Assume the distribution can be described by a Normal model.

a) If one car is randomly selected, find the probability that its CO level is between 2.3 gm and 3.5 gm/mi.

b) There is an 18% chance that the fleet’s mean CO is greater than what value?