Costs $3.75 / gallon
C(n) = 3.75 * n
Domain is the set of values for n.
n is the number of gallons, which has to be a number between 0 and 5000.
Then, the domain is all real numbers in the interval [0 , 5000].
The range is the set of values that the function, C(n) can take.
The minimum value of C(n) = 3.75n is 0*$3.75 = 0.
The maximum value of C(n) is C(n) = 5000*$3.75 = $18750
And C(n) is continuous meaning that it can take any real value between 0 and $18750.
So, the range of the tuncion C(n) is [0, 18750].
