Question

mike’s bikes has mountain bikes that usually sell for $275 on sale for $220. mike used this ratio to find the percent change. is he correct? explain.\\(\frac{55}{220} = 25\\%\\)

Explanation:

Step1: Recall Percent Change Formula

Percent change formula is $\frac{\text{Amount of Change}}{\text{Original Amount}} \times 100\%$. The original price is $275, sale price is $220. Amount of change is $275 - 220 = 55$.

Step2: Apply the Formula

Using the formula, percent change should be $\frac{55}{275} \times 100\%$. Simplify $\frac{55}{275}=\frac{1}{5}= 0.2 = 20\%$, not $\frac{55}{220}$. Mike used the sale price as the original amount, which is incorrect.

Answer:

Mike is not correct. The percent change formula uses the original amount (275) as the denominator, not the sale price (220). Correct calculation: $\frac{275 - 220}{275}=\frac{55}{275}=20\%$, so his ratio is wrong.