Question

John spent $75 on a shopping trip for new clothes last week. He had expected to spend $100 on clothes. Complete the table.John's sister went shopping with him. She expected to spend $100 on clothes, but spent only $10. John wanted to help her calculate the percent error, but he thinks he may have made a mistake. Are his calculations below correct? Why or why not?
Johns Calculations: 100-10 10
--------- = ----- is approximately 11%
90 90

Answer 1

John’s calculations are not correct. He compared the exact value to the absolute error. The absolute error should be in the numerator and the exact value in the denominator.

Answer 2

Answer:

Amount Possessed by John's sister = $ 100

Amount spent on buying clothes = $ 10

So, % of money spent on buying clothes by john's sister

         = $\frac{\text{ Amount spent by john's sister}}{\text{Amount possessed by john's sister }}\times 100=\frac{10}{100}\times{100} = 10$%

Johns Calculations: 100-10 10

--------- = ----- is approximately 11%

90 90 is incorrect.