To find the percent error when estimating the number of marbles in the jar, you can use the formula:
Percent Error = [(|Estimated Value - Actual Value|) / Actual Value] x 100%
1. Given that the estimated number of marbles is 56 and the actual number is 78, you would substitute these values into the formula:
Percent Error = [(|56 - 78|) / 78] x 100%
2. Calculate the difference between the estimated and actual values:
|56 - 78| = |-22| = 22
3. Substitute the values into the formula:
Percent Error = [22 / 78] x 100%
4. Divide to find the decimal value:
22 / 78 ≈ 0.282
5. Convert the decimal to a percentage by multiplying by 100%:
Percent Error ≈ 0.282 x 100% ≈ 28.2%
Therefore, the percent error when estimating 56 marbles in a jar when there are actually 78 marbles is approximately 28.2%.
