Bear with me, I cannot format on Stack Exchange, but I will do my best to explain.
I need to calculate the proportion of claims above a certain point.
I have my expectation and variance hats.
I'm being told I should calculate this data from a lognormal distribution above a given point, but to do it via TI 84 I must convert the lognormal parameters and boundaries to normal. I do not know how to do this.
So specifically I have lognormal ML estimators as mu hat = 5.75, sigma squared hat = .16, and I need to know what the proportion that exceed 400 is.
EDIT: I found a calculator online, and I knew I would, but asked this anyway in case I had to calculate the cdf on a test.
The lognormalCDF(400, 5.75, .4) = 0.726965598
So the complement is 1 - 0.726965598 = .273034402 = P(X>400)