Please help with cost functions!

[skyflow3r]

For cost function C(x) = 67600+800x+x^2 Find? production level is 1700.
1. The production level that will minimize the average cost
-i found this to be 400, i just dont understand how to use this answer to answer #2. I know c(1700)/(1700) is the formula? HOw do i solve this to get #2'a answer? wouldnt that just be c1??

2. The minimal average cost

thanks for any help!

 

[tkhunny]

Find what for a production level of 1700?

Cost? C(1700)
Average Cost? C(1700)/1700

How did you get 400? Did you find the first derivative of C(x)/x? Taht would be a good start. It's not 400.