I used an old training example with a reference and unknow curve. I get this after fitting a Logistic 4P model:
![Fit Curve Model Comparison and PLot.png Fit Curve Model Comparison and PLot.png](/t5/image/serverpage/image-id/67211i55D7BFAD2CBAE7DA/image-size/large?v=v2&px=999)
![Fit Curve Logistic 4P.png Fit Curve Logistic 4P.png](/t5/image/serverpage/image-id/67212i3FF68DE0577AEA05/image-size/large?v=v2&px=999)
What version of JMP are you using? How did you start your analysis? Can you share a picture of the launch dialog you used? Which model did you select from the red triangle menu? What other information appeared in the window after you fit the model?