Webrooming, researching products online before buying them in store, has become the new norm for some consumers and contrasts with showrooming, researching products in a physical store before purchasing online. A recent study by Interactions reported that most shoppers have a specific spending limit in place while shopping online. Findings indicate that men spend an average of $250 online before they decide to visit a store.

Assume that the spending limit is normally distributed and that the standard deviation is $20.

a. What is the probability that a male spent less than $210 online before deciding to visit a store?

b. What is the probability that a male spent between $270 and $300 online before deciding to visit a store?

c. Ninety percent of the amounts spent online by a male before deciding to visit a store are less than what value?

d. Eighty percent of the amounts spent online by a male before deciding to visit a store are between what two values symmetrically distributed around the mean?