Consider the data below of inches of rainfall per month for two different regions in the Northwestern United States:

Plains Mountains

April 20.1 12.9

May 15.3 17.8

June 19.8 15.4

July 17.4 11.2

August 16.8 13.7

Using SPSS, perform a two-sample t-test against the hypothesis that there is not the same amount of rainfall in both regions in the Northwestern United States with a significance level of 0.05. What are the degrees of freedom of your test statistic?

**Subject Mathematics Advanced Statistics**