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%

If the error in an estimate is a negative number, what does this indicate about the estimate?

• The estimate was exactly correct.

• The estimate was higher than the actual value.

• The estimate was lower than the actual value.

• The estimate was off by a large amount.

A restaurant owner estimated 110 customers for dinner, but 125 customers actually came. What is the percent error for this estimate?

• 15%

• 12%

• 10%

• 25%

A restaurant owner made two estimates. The lunch estimate had a percent error of 25%, and the dinner estimate had a percent error of 12%. Which estimate was more accurate?

• The lunch estimate was more accurate.

• The dinner estimate was more accurate.

• Both estimates were equally accurate.

• Neither estimate was accurate.

What does a lower percent error indicate about an estimate's accuracy?

• The estimate is less accurate.

• The estimate is more accurate.

• The estimate is exactly correct.

• The estimate is impossible to determine.