Answer
The math is below, and the graph is attached.
Work Step by Step
We plug in the given values of x into the equation to find:
A) $f(50) = 12 + .2(50) = 22$
B) $ f(100) = 12 + .2(100) = 32$
C) The graph is attached.
D) In order to estimate, first draw a vertical line at t=80. Then, estimate the value of f(x) at the intersection. This value is 28 gallons. After all:
$f(80) = 12 + .2(80) = 28$
