Salaries for various positions can vary significantly, depending on whether or not the company is in the public or private sector.The U.S. Department of Labor posted the 2007 average salary for human resource managers employed by the federal government as $76,503. Assume that annual salaries for this type of job are normally distributed and have a standard deviation of $8850.
a. What is the probability that a randomly selected human resource manager received over $100,000 in 2007?
b. A sample of 20 human resource managers is taken and annual salaries are reported.What is the probability that the sample mean annual salary falls between $70,000 and $80,000?