The age of real estate investors is normally distributed with a mean of 38 years and a standard deviation of 9.1 years.

1.What is the probability that a randomly selected real estate investor is under 25 years of age?

2.Calculate the age under which are 10% of investors.

3.If a random sample of 20 real estate investors is selected find the probability that their average age is more than 40.

4.For the calculation in c. did we need to be told (in a.) that investors' ages are normally distributed? Explain.

5.Explain what a z score is. Then explain why the Standard Normal Distribution is important in doing statistical calculations.