Calculus!!
Find the marginal average profit at 40
P(x)=60x-.2x^2-290

Question

emac · Answer

I know P'(x)=60-.4x and I've plugged in 40 and gotten 44

then I divided 44/40 and got 1.1 which is the wrong answer

caozeyuan · Answer

your math looks right to me, I've never heard of econ before, so cant comment on that part

518nad · Answer

what is the definition of marignal avg profit

emac · Answer

I thought it was C'(x)/x

emac · Answer

Because I wanted to find the marginal average profit at 40

jim_thompson5910 · Answer

@emac see page two http://www.math.tamu.edu/~jlewis/142notesMarginalAn.pdf where it says `A common mistake is to find the average marginal profit` Just above that, they describe how to find the marginal average profit. Step 1) Find the average profit, which is equal to P(x)/x Step 2) Apply the derivative to whatever you got in step 1

emac · Answer

I got P'(x)=(-x^2-1450)/5x^2 and when I plugged 40 in I got the correct answer of -3/160. Thank you!!