title: How to find the argument of scipy.stats.exponnorm given certain parameters and output
body: <p>My problem is as follows:
  Consider two PDFs - one normal distribution (let's call it norm) , and one exponentially modified normal distribution (exponorm). Given a point X, F is the fractional ratio of the area of norm and the area of exponorm between point X and infinity. I.e. F = (1 - exponorm.CDF(X))/(1 - norm.CDF(X)) .</p>
  <p>I am specifically looking at the scipy function <a href="https://docs.scipy.org/doc/scipy/reference/generated/scipy.stats.exponnorm.html" rel="nofollow noreferrer">https://docs.scipy.org/doc/scipy/reference/generated/scipy.stats.exponnorm.html</a>, and trying to work out how I can input a value for F, as well as all other parameters norm and exponorm require, and then output a value for K as defined in the link.</p>
  <p>Tl;dr how do I extract an argument for a PDF given a value for the CDF and all other parameters.</p>
  <p>Thanks in advance :)</p>