When calculating percent error, just take the ratio of the amount of error to the accepted value or true value, or real value. Then, convert the ratio to a percent.

We can expresss the percent error with the following formula shown below:

Keep in mind that when computing the amount of error, you are always looking for a positive value.

Therefore, always subtract the smaller value from the bigger. In other words, amount of error = bigger − smaller

A student made a mistake when measuring the volume of a big container. He found the volume to be 65 liters.

However, the real value for the volume is 50 liters. What is the percent error?

Percent error = (amount of error)/accepted value

amount of error = 65 - 50 = 15

The accepted value is obviously the real value for the volume, which 50

So, percent error = 15/50

Just convert 15/50 to a percent. We can do this multiplying both the numerator and the denominator by 2

We get (15 × 2)/(50 × 2) = 30/100 = 30%

A man measured his height and found 6 feet. However, after he carefully measured his height a second time, he found his real height to be 5 feet.

What is the percent error the man made the first time he measured his height?

Percent error = (amount of error)/accepted value

amount of error = 6 - 5 = 1

The accepted value is the man's real height or the value he found after he carefully measured his height, or 5

So, percent error = 1/5

Just convert 1/5 to a percent. We can do this multiplying both the numerator and the denominator by 20

We get (1 × 20)/(5 × 20) = 20/100 = 20%

I hope what I explained above was enough to help you understand what to do when calculating percent error

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