The average starting salary for this year's graduates at a large university (LU) is $50,000 with a standard deviation of $10,000. Furthermore, it is known that the starting salaries are normally distributed.

a. What is the probability that a randomly selected LU graduate will have a starting salary of at least $45,000?

b. Individuals with starting salaries of less than $36,900 receive a low income tax break. What percentage of the graduates will receive the tax break?

c. What are the minimum and the maximum starting salaries of the middle 95% of the LU graduates?

d. If 300 of the recent graduates have salaries of at least $65,000, how many students graduated this year from this university?