Edited out incorrect formula
Can someone please solve this equation for x? I have no idea what to do with the $\mathrm{erf}$ (error function).
Edit: Hm, it did not work correctly... here is the function I meant to solve for x in symbolic form:
$f(x) = a*\left(0.5*\mathrm{erf}\left(\frac{x-b}{c\sqrt{2}}+.5\right)\right)+d$
Coefficients (with 99% confidence bounds): a = 1.412 (1.411, 1.412) b = 1.259 (1.259, 1.259) c = 1.003 (1.002, 1.003) d = 0.3016 (0.3014, 0.3017)
When I solve for f(x) with x=1
I get ans = 0.5460
I want to plug 0.5460
into a formula and get 1
back.
Chris, this is the Finv function you spoke of in my other question.