According to her running log, Shivani averaged 3.2 miles per week last month and 2.8 miles per week this month. By what percent has her average decreased
To calculate the percent decrease, we need to find the difference between the two averages and express it as a percentage of the initial average.
The difference between the averages is 3.2 - 2.8 = 0.4 miles per week.
To express this difference as a percentage of the initial average, we divide by the initial average and multiply by 100.
0.4/3.2 * 100 = 12.5%.
Therefore, Shivani's average has decreased by 12.5%.