Answer: Percent change = 20%
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Work Shown:
A = old value = 25 (last week's number)
B = new value = 30 (current week's number)
C = percent change
C = [ (B-A)/A ] * 100%
C = [ (30-25)/25 ] * 100%
C = [ 5/25 ] * 100%
C = 0.20* 100%
C = 20%
The percent change is 20%
The positive value of C indicates we have a percent increase.