Diagnostic Test 1 Practice Test

For the function $f(x)=x^2 - x$, what is the value of $f(9)-f(7)$?

Over five different years, the total rainfall in Brooks County was, in ascending order, 15 inches, 24 inches, $x$ inches, 45 inches, and 60 inches. If the average annual rainfall was equal to the median annual rainfall for those five years, what was the average rainfall?