Final answer:
To find the percent error, subtract the assumed number of problems correct from the actual number of problems correct, divide by the assumed number of problems correct, and multiply by 100. The percent error is approximately 22%.
Step-by-step explanation:
To find the percent error, we need to calculate the difference between the assumed number of problems correct and the actual number of problems correct, divide that difference by the assumed number of problems correct, and then multiply by 100 to get the percentage. In this case, the assumed number of problems correct is 64 and the actual number of problems correct is 78.
Difference = Actual - Assumed = 78 - 64 = 14
Percent Error = (Difference / Assumed) * 100 = (14 / 64) * 100 = 21.88%
Rounding to the nearest percent, the percent error is approximately 22%.