Newton's Law of Cooling is used in homicide investigations to determine the time of death. The normal body temperature is 98.6°F. Immediately following death, the body begins to cool. It has been determined experimentally that the constant in Newton's Law of Cooling is approximately k = 0.1947, assuming time is measured in hours. Suppose that the temperature of the surroundings is 65°F.
(a) Find a function T(t) that models the temperature t hours after death.
(b) If the temperature of the body is now 71°F, how long ago was the time of death? (Round your answer to the nearest whole number.)