The annual salaries of employees in a large company are approximately normally distributed, with a mean of $50,000 and a standard deviation of $20,000.

(a)What is the probability that an employee earns a salary greater than $100,000?

(b)The company provides free public transport to the employees that earn the lowest 10% of salaries. Less than what salary does a person have to earn to qualify for the free public transport?

(c)A sample of 16 employees is now taken. What is the probability that the sample mean is greater than $40,000?