Question

Ross needs to buy a countertop for a laundry room. He calculated the area to be 12 square feet. The actual area is 11.8 square feet. What is Ross's percentage error?

Answer 1

The formula for percentage error is:

$\sf{Percentage~ error= \frac{|Approximate ~-~ Actual|}{|Actual|}}$

Ross got the approximate area as 12, while the actual area was 11.8. So, let's plug it in to the formula.

$\sf{Percentage~ error= \frac{|Approximate ~-~ Actual|}{|Actual|}= \frac{|12-11.8|}{|11.8|}= \frac{|0.2|}{|11.8|}= \frac{0.2}{11.8} \approx 0.0169 }$

Multiply 0.0169 by 100 to make it into a percent.

0.0169 * 100 = 1.69%

Ross's percentage error is 1.69%.