This is how you set up a percent of error proportion: <u>Amount of error</u> <u>x(Unknown percent)</u> Actual value = 100(Percents are out of hundreds)
So if you fill it in, it becomes <u>4</u> <u>x </u> 80 =100 Cross multiply, 400= 80x. Solve. x=5 so percent error is 5%<u> </u>