The temperature of a cup of coffee changed by \( -54^{\circ} \mathrm{F} \) over \( 22 \frac{1}{2} \) minutes. What was the change in temperature each minute?

To find the change in temperature each minute, you can divide the total temperature change by the total time in minutes. The total temperature change is \( -54^{\circ} \mathrm{F} \), and the time is \( 22.5 \) minutes or \( 22 \frac{1}{2} \) minutes. So, the calculation is: \[ \text{Change per minute} = \frac{-54}{22.5} \approx -2.4^{\circ} \mathrm{F} \] This means the temperature of the coffee decreased by about \( 2.4^{\circ} \mathrm{F} \) every minute. Always remember to keep track of your units, especially when working with temperature changes, to avoid any confusion! It's also a good idea to double-check your math by multiplying your per-minute change by the total time to ensure it matches with the total change.