T = 24* 0.91^t
Step-by-step explanation:
The initial temperature of coffee = 96°F
The temperature at room temperature = 72°F
The difference in temperature between initial temperature and room temperature:
96°F - 72°F = 24°F
We are told the difference decrease every minute by 9%
In one minute, decrease:
100% - 9% = 91%
Due to decrease every minute, it would be an exponential function. The decrease raised to power of time.
The function describing the temperature of the coffee as a function of time: