Answer
(a) 72$^{\circ}$F at about 4:30 p.m.
(b) 4$^{\circ}$F/h
(c) −7$^{\circ}$F/h at about 9 p.m.
Work Step by Step
a) The maximum temperature and the time at which it occurs.
-- 72◦F at about 4:30 p.m.
b) The temperature rise is fairly linear from 8 a.m. to 2 p.m. The rate at which the temperature is increasing during this time period
-- 4◦F/h
c) The time at which the temperature is decreasing most rapidly. The instantaneous rate of change of temperature with respect to time at this instant.
-- −7◦F/h at about 9 p.m.
