In order to find the percent increase from 50 to 90, first let's find the absolute increase, calculating the difference between the numbers:
[tex]90-50=40[/tex]The increase was 40 units. Now, to find the percent increase, we just need to divide this absolute increase by the initial value:
[tex]\frac{40}{50}=\frac{4}{5}=0.8=80\text{\%}[/tex]So the percent increase is 80%.
