Answer:
=65 181/290
Step-by-step explanation:
The minimum cost is arrived to when ΔC/Δx is zero.
ΔC/Δx= 2.2x-638
We equate this to zero to get the minimum.
2.2x-638=0
2.2x=638
x=290
The cost for 290 engines is given by:
C(x)=1.1x²-638x+111,541
We replace the value of x above in this function.
=1.1(290)²-638(290)+111541
=19 031
Then 1 unit costs 19031/290
=65 181/290