## The Normal Distribution: Exercise #4

**Objective:**

**Problem Description**
Average yearly rainfall totals for various cities in Oregon have been
kept for every year for the last 125 years. These rainfall amounts
follow approximate Normal distributions with different means and
standard deviations for each city. For this exercise we'll consider
three cities and look at their annual rainfall. Selma, Oregon has a
mean of 100 inches of rainfall per year with a standard deviation of
10 inches of yearly rainfall. Thaynesville, Oregon has a mean annual
rainfall of 100 inches with a standard deviation of 5 inches. Glen
Falls, Oregon has a mean annual rainfall of 105 inches with a standard
deviation of 10 inches. Use this information to answer the following
questions about rainfall totals for 2001.

The following normal Java applet displays the
probabilities of a normal random variable, *X*, initially with
a mean of 100 in and a standard deviation of 10 in. You will need to
change the mean and standard deviation depending on the city. Use this
applet to answer the questions below.