dmcgraw23

I'm running analytics and need help setting up my formula. I remember from my calculus days there is a formula to find the optimal output but I cant remember, here is what I'm looking for: I have a total rev per patient and I have total number of patients seen. Ive noticed as the number of patients increase the rev per patient decreases. I'm trying to find the optimal number of patients seen to have the highest rev per patient. rev per patient tot patients 248.89 906 240.19 851 227.03 947 252.67 896 276.60 772 261.17 864 286.15 752 282.75 843 280.70 845 274.36 873 239.12 980