Carbon monoxide (CO) emissions for a certain kind of car vary with mean 2.646 g/mi and standard deviation 0.8 g/mi. A company has 80 of these cars in its fleet. Let y represent the mean CO level for the company's fleet. a) What's the approximate model for the distribution of y? Explain. b) Estimate the probability that y is between 2.7 and 2.8 g/mi. c) There is only a 5% chance that the fleet's mean CO level is greater than what value?

There were 127 pears and oranges in a box at first. 2/5 of the pears and 2/3 of the oranges were given away. In the end, there were a total of 65 pears and oranges left. How many more pears than oranges were in the box at first?