Answer
domain:
$\left\{\text{Less then 9th grade, 9th-12th grade, High School Graduate,}
\\\text{Some College, College Graduate}\right\}$
range:
$\left\{\text{\$18,120, \$23,251, \$36,055, \$45,810, \$67,165}\right\}$
The relation is a function.
Work Step by Step
The domain is the set of the first coordinates while the range is the set of second coordinates.
Thus, the given relation has:
domain:
$\left\{\text{Less than 9th grade, 9th-12th grade, High School Graduate,}
\\\text{ Some College, College Graduate}\right\}$
range:
$\left\{\text{\$18,120, \$23,251, \$36,055, \$45,810, \$67,165}\right\}$
Every first element is paired/mapped with only one second element so the relation is a function.
