1. Kylie is an economic consultant studying annual incomes for the population of workers in L.A. County. She knows that income (X) is normally distributed, with a mean of $60,000 and a standard deviation of $20,000.

a. What percentage of L.A. County workers earn more than $85,000 per year?

b. What percentage of L.A. County workers earn between $50,000 and $70,000 per year?

c. If Kylie took a random sample of 30 L.A. County Workers, what is the probability that the sample mean income would exceed $50,000? (Round your answer to two decimal places.)