# Inverse 4-parameters Cumulative Weibull Distribution

May someone write the inverse of the FOUR-parameters Weibull cumulative distribution (percent point function), please? I am referring to the 4-parameters formula appearing in Sigmaplot.

• There probably is no formula for the inverse. May 31 at 19:55
• Existing for the three-parameters distribution, I wonder if it also exists for the four-parameters one. Jun 1 at 6:29