The U.S. Bureau of Economic Statistics reports that the average annual salary in the metropolitan Boston area is $50,542. Suppose annual salaries in the metropolitan Boston area are normally distributed with a standard deviation of $4,246. A Boston worker is randomly selected.

a. What is the probability that the worker's annual salary is more than $60,000?

b. What is the probability that the worker's annual salary is less than $45,000?

c. What is the probability that the worker's annual salary is more than $40,000?

d. What is the probability that the worker's annual salary is between $44,000 and $52,000?