Answer:
The answer is "140".
Step-by-step explanation:
Calculating the average cost:
[tex]= \frac{C(x)}{x}\\\\ = \frac{19600+500x+x^2}{x} \\\\ = \frac{19600}{x}+500 +x\\\\[/tex]
To minimize average cost we have to find x for wich A'(x)=0
[tex]A(x) = \frac{19600}{x}+500 +x \\\\A'(x) = -\frac{19600}{x^2}+1 \\\\0= -\frac{19600}{x^2}+1 \\\\\frac{19600}{x^2}=1 \\\\19600=x^2 \\\\x=140[/tex]