#### Answer

We can estimate the values of $W'(x)$:
$x = 15.5: W'(x) = -2.82$
$x = 17.7: W'(x) = -3.87$
$x = 20.0: W'(x) = -4.53$
$x = 22.4: W'(x) = -6.73$
$x = 24.4: W'(x) = -9.75$
We can use the estimates of $W'(x)$ to sketch the graph of $W'(x)$
The units of $W'(x)$ are grams per degree Celsius.

#### Work Step by Step

We can estimate the values of $W'(x)$:
$x = 15.5: W'(x) = \frac{31.0-37.2}{17.7-15.5} = -2.82$
$x = 17.7: W'(x) = \frac{19.8-37.2}{20.0-15.5} = -3.87$
$x = 20.0: W'(x) = \frac{9.7-31.0}{22.4-17.7} = -4.53$
$x = 22.4: W'(x) = \frac{-9.8-19.8}{24.4-20.0} = -6.73$
$x = 24.4: W'(x) = \frac{-9.8-9.7}{24.4-22.4} = -9.75$
We can use the estimates of $W'(x)$ to sketch the graph of $W'(x)$
The units of $W'(x)$ are grams per degree Celsius.