Question

what is the approximate percent change in a temperature that went down from 120 degrees to 100 degrees?
the percent change is approximately 17%.
the percent change is approximately 20%.
the percent change is approximately 80%.
the percent change is approximately 120%.

Explanation:

Step1: Recall Percent Change Formula

The formula for percent change is $\text{Percent Change} = \frac{\text{New Value} - \text{Old Value}}{\text{Old Value}} \times 100\%$. Here, old value is 120, new value is 100.

Step2: Substitute Values

Substitute into the formula: $\frac{100 - 120}{120} \times 100\% = \frac{-20}{120} \times 100\%$.

Step3: Calculate the Result

Simplify $\frac{-20}{120} \approx -0.1667$, then multiply by 100%: $-0.1667 \times 100\% \approx -16.67\%$, which is approximately 17% (the negative sign indicates a decrease, but we consider the magnitude for approximation here).

Answer:

The percent change is approximately 17% (the option: The percent change is approximately 17%).