A function is a viable probability function if it has a valid CDF (i.e., is bounded by zero and one) which is the integral of the probability density function (pdf). The inverse CDF (aka, quantile function) returns the quantile associated with a probability, q = F^(-1)(p), whereas the CDF returns the probability associated with a quantile: p = F(q).
As mentioned, the =POISSON_INV(.) is not built into excel. Rather, it is available from the wonderful and *free* add-on published by Charles Zaiontz and available at http://www.real-statistics.com
David's XLS: http://trtl.bz/2AgvfRo
As mentioned, the =POISSON_INV(.) is not built into excel. Rather, it is available from the wonderful and *free* add-on published by Charles Zaiontz and available at http://www.real-statistics.com
David's XLS: http://trtl.bz/2AgvfRo
