How do you calculate percentage of improvement?

The goal is 15%. Last week it was 15.79%. This week it is 18.60%. How much has the sales improved?



Thank you!!How do you calculate percentage of improvement?
increase=(1.1579)(1.186)

=1.3733

improvement=37.33%How do you calculate percentage of improvement?
It sound harder than it is. Since it's already a percentage, sales have increased 2.81%How do you calculate percentage of improvement?
Let the sales two weeks back be 100

Last week it was 115.79

This week it is 118.60/100 X 115.79 = 137.33



at the rate of 15.79 it should have been 115.79 x 1.1579 = 134.07



so increase is 137.33 - 134.07 = 3.25