An Intro to Percent Error | Math with Mr. J

What is the main purpose of calculating percent error?

• To find the exact value of a measurement.

• To see how far off an estimate is from the actual value.

• To convert a decimal to a percentage.

• To determine if an estimate is positive or negative.

Which formula correctly represents how to calculate percent error?

• (Actual - Estimated) / Estimated * 100

• |Measured or Estimated - Actual| / Actual * 100

• (Measured + Actual) / 2 * 100

• |Actual - Measured or Estimated| * 100

In the first example, a restaurant owner estimated 45 customers for lunch, but 36 actually came. What is the error in the owner's estimate?

• 9

• -9

• 45

• 36

Using the information from the first example (estimated 45 customers, actual 36 customers), what is the percent error?

• 20%

• 25%

• 9%

• 36%