Answer:
"34,814" is the correct solution.
Step-by-step explanation:
The given values are:
Intercept coefficient,

Production coefficient,
Units sold,
x = 3,500
Now,
The total cost will be:
⇒ 
On substituting the estimated values, we get
⇒ 
⇒ 
⇒ 
The area of the trapezoid :

the area of the triangle :
first you should find the height

now :

the area of the whole shape :

the answer is 19ft^2
good luck