At the start of the week, you could run for 8 minutes. By the end of the week, you could run for 15 minutes. Which proportion could you use to find the percent increase in your running time?
The formula for finding percent increase is: (Final - Initial)/Final * 100 = n Divide both sides by 100 and you get: (final-initial)/Final = n/100 Plug in all the numbers, and you get: (15-8)/15 = n/100, or 7/15 = n/100