As the number of units manufactured increases from 4000 to 6000 the total cost of production increases form $22000 to $30000. Assuming a linear relationship between the cost and the number of units manufactured, what will be the cost when 4500 units are produced.

Answer 1

everything in thousands
two points on line
(4,22) and (6,30)

(30-22)/(6-4) = slope
so slope = m = 4
c = 4 n + b
22 = 16 + b
b = 6
so
c = 4 n + 6
if n = 4.5
c = 4(4.5) + 6
c = 18+6
c = 24
so
24,000