Salaries of a major airline have an average salary of $2.5 million with a standard deviation of $3.5 million last year. Assume that salary is normally distributed. Suppose a sample of 64 employee was taken.

(a) What is the standard error for the sample mean salary?

(b) What is the probability that the sample mean salary is more than $3 million?

(c) What is the probability that the sample mean salary is less than $2 million?

(d) What is the probability that the sample mean salary is between than $2.5 million and $3.2 million?