Question

A certain store sells only T-shirts. Let the random variable X represent the number of T-shirts bought from the store on any day, with a mean of 75 and a standard deviation of 20. Let the random variable Y be the total revenue from this store on a randomly selected day. If the store charges $15 per T-shirt, what are the mean and standard deviation of Y

Answer 1

Explanation:

Given

-- Mean of T-shirts

-- Standard deviation of T-shirts

Solving (a): The mean of the revenue

To solve this, we use:

This gives:

Solving (b): The standard deviation of the revenue

To solve this, we use:

This gives: