Answer:
25
Explanation:
Formula for percent increase or decrease:
(new number - old number)/(old number) * 100%
In this case,
old number = $28
new number = $21
Plug numbers into formula:
($21 - $28)/($28) * 100%
= -$7/$28 * 100%
= -0.25 * 100%
= -25%
A negative answer means a percent decrease.
A positive answer means a percent increase.
The percent change here is -25%, so it is a percent decrease of 25%