Given that:
this year you earned 75,500. Last year you earned $72,400.
So the rate of change on your earnings last year.:
[tex]\begin{gathered} Avg_{rate}=\frac{75500-72400}{1\text{ year}} \\ Avg_{rate}=\frac{3100}{1} \\ Avg_{rate}=3100 \end{gathered}[/tex]Hence the rate of change on your earnings last year is $3100
