Question

PLEASE ANSWER ASAP
At the school carnival students guessed how many marbles are in a jar. Marlo guessed 84 when it was actually 80.
What percent of error did Marlo have?

Answer 1

This is how you set up a percent of error proportion:
Amount of error       x(Unknown percent)
Actual value      =   100(Percents are out of hundreds)


So if you fill it in, it becomes 4      x
                                                80 =100
Cross multiply, 400= 80x.
Solve.
x=5 so percent error is 5%