Hello all. I'd like to find a basic formula for an S curve calc in

excel. Variables would be equal to Y = moeny vs. X time (or period).

Ymax would be the budgeted cost of the project, and Xmax would be the

budgeted time for the project.

current calculation I'm using is:

Y = Ymax ((2(X/Xmax)^2) - (X/Xmax)^4)

While this does give me a curve, I need a curvier curve.

Any

help would be appreciated.

Thanks!