Question

Alberto measures the length of a piece of wire to be 105 cm. The actual length of the wire was 120 cm. What was the percent error of Alberto's measurement? Show your work. ​

Answer 1

12.5%

Explanation:

105 over 120 is the fraction that he got so you subtract 105 from 120 to get how much he missed. 120-105=15

He miscalculated by 15 cm out of the total of 120, 15/ 120

15/120=5/40=2.5/20 multiply the top and bottom by 5 to get the percentage out of 100. 2.5 times 5 =12.5, so he miscalculated by 12.5%