Weibull 10 50 90
Defines a translated Weibull distribution having the indicated 10-50-90 percentiles, if possible. A translated Weibull distribution has an underlying form Weibull(a,b)+c
Not all combinations of fractiles can be fit exactly. It can be shown that no Weibull distribution has fractiles satisfying $ (x50-x10) / (x90-x50) > 1.569 $. Thus, if your fractiles have skew exceeding this limit, the resulting distribution will not fit the fractiles exactly. In that case, a distribution in the general vicinity is returned (i.e., it'll do the best it can)
To use this function, you must first add the Distribution variations function library to your model.