Exercise 106

Take an example in the source text with the same numbers: 89 degrees at $t=0$, 85 degrees at $t=1$, and ambient temperature of 22 degrees. Suppose these temperatures were measured with a precision of $\pm 0.5$ degrees. Given this imprecision, the time it takes the coffee to cool to (exactly) 60 degrees is also only known in a certain range. Find this range. Hint: Think about what kind of error makes the cooling time longer and what shorter.