Question

Martha estimated there were 86 marbles in a jar for a contest. The actual number of marbles in the jar was 107. What was the

percent error of Martha's estimation?

Answer 1

Roughly 20.4%

Explanation:

Use the formula of percent of error:

| Actual number - Guess / Actual number | (100)

The actual number is 108 and the guessed number is 86:

| 108 - 86 / 108 | (100)

= | 22/108 | (100)

= | 0.2037037037 | (100)

The vertical lines indicate absolute value. This means that anything inside of it must be turned into its positive form. Since it is already positive, just take the signs away:

0.2037037037(100)

≈ 0.204(100)

= 20.4

Turn this into a percent:

20.4%

Martha's percent of error is 20.4%

Please tell me if I was right or not. I really hope this helps!