Answer
a) $-4.05^{\circ}F/min$
b) $-1.5^{\circ}F/min$
c) Tthe soap cool up quickly in the first interval.
Work Step by Step
a) The average rate is given as: $\dfrac{f(b)-f(a)}{b-a}$ where $a \leq b$
$\dfrac{f(20)-f(0)}{20-0}=\dfrac{119-200}{20}=-4.05^{\circ}F/min$
b) Apply the rule such as
The average rate is given as: $\dfrac{f(b)-f(a)}{b-a}$ where $a \leq b$
$\dfrac{f(40)-f(20)}{40-20}=\dfrac{89-119}{20}=-1.5^{\circ}F/min$
c) We can see that the soap cool up quickly in the first interval.
