Final answer:
The mean CO level for the company's fleet (y) is distributed approximately normally with a mean of 2.352 g/mi and a standard deviation of 0.0717 g/mi, based on the central limit theorem and given sample size of 70 cars.
Step-by-step explanation:
The distribution for the mean CO level for the company's fleet can be approximated by the central limit theorem which states that the sampling distribution of the sample means will be approximately normally distributed if the sample size is large enough, regardless of the shape of the population distribution.
Given that the mean CO emissions for a certain kind of car is 2.352 g/mi with a standard deviation of 0.6 g/mi, and the company has 70 cars in its fleet, we can use the central limit theorem to find the distribution of y, the mean CO level for the company's fleet.
Since the sample size is 70, which is greater than 30, it's often considered large enough for the central limit theorem to apply. The expected mean (μy) of the sampling distribution of y is equal to the population mean (μ), which is 2.352 g/mi. The standard deviation (σy) of the sampling distribution, also known as the standard error, is the population standard deviation (σ) divided by the square root of the sample size (n), which is 0.6/sqrt(70), or approximately 0.0717 g/mi.
The approximate model for the distribution of y is, therefore, a normal distribution with mean μy = 2.352 g/mi and standard deviation σy = 0.0717 g/mi.