Question

1. you made a grocery list and estimated you would spend $100 at the store. some items were on sale and you wound up spending $80. what was your percent error?

Explanation:

Step1: Recall the formula for percent error

The formula for percent error is $\text{Percent Error}=\frac{\vert\text{Estimated Value}-\text{Actual Value}\vert}{\text{Actual Value}}\times100\%$.

Step2: Identify the estimated and actual values

The estimated value is $\$100$ and the actual value is $\$80$.

Step3: Calculate the difference between estimated and actual values

$\vert100 - 80\vert=\vert20\vert = 20$.

Step4: Substitute into the percent - error formula

$\text{Percent Error}=\frac{20}{80}\times100\%$.

Step5: Simplify the fraction

$\frac{20}{80}=\frac{1}{4}$.

Step6: Calculate the percentage

$\frac{1}{4}\times100\% = 25\%$.

Answer:

$25\%$