I am doing work with confidence intervals for normally distributed data and I want to be able to calculate specific intervals (such as .92, etc). If x is the mean and y is the std dev I know that CI=(x-ny,x+ny), where n=sqrt(2)*inverseERF(CI).
I tried to make a vba function to calculate the invERF, but I'm off by a bit.
Does anyone know of an existing invERF funcion? I can't find actual code for one anywhere.
Thanks,
Pete
I tried to make a vba function to calculate the invERF, but I'm off by a bit.
Does anyone know of an existing invERF funcion? I can't find actual code for one anywhere.
Thanks,
Pete