
Answer:
Step-by-step explanation:
The initial temperature difference of 72 -34 = 38 °F is reduced to a difference of 72 -41 = 31 °F after 35 minutes. The exponential term in the temperature expression could have the factor ...
 (31/38)^(t/35) = e^(-kt)
Taking the natural log, we find ...
 (t/35)ln(31/38) = -kt
 k = ln(38/31)/35 ≈ 0.00581711
To the nearest thousandth, this is ...
 k ≈ 0.006
Using this in the equation for temperature, we have ...
 T = 72 -38e^(-0.006t)
Filling in the desired value for t (80), we find the turkey temperature after 80 minutes to be about
 T = 72 -38e^(-.006×80) = 72 -38e^-.48 ≈ 48.49
 T ≈ 48 °F
The value of k is about 0.006, and the turkey temperature is about 48 °F.