## Thinking Mathematically (6th Edition)

A decrease of $15^{\circ}$ Celsius is more than a decrease of $15^{\circ}$ Fahrenheit.
$F = \frac{9}{5}C+32$ We can use this formula to convert from Celsius to Fahrenheit. The factor of $\frac{9}{5}$ means that for every $1^{\circ}$ change in temperature on the Celsius scale, there is a $(\frac{9}{5})^{\circ}$ change in temperature on the Fahrenheit scale. If the temperature decreases $15^{\circ}~C$, we can find the decrease on the Fahrenheit scale. $(\frac{9}{5})~(15^{\circ}) = 27^{\circ}~F$ This is more than a decrease of $15^{\circ}~F$. Therefore, a decrease of $15^{\circ}$ Celsius is more than a decrease of $15^{\circ}$ Fahrenheit.