Hi,

I am sorry, there was a typo in the second equation in my previsous response
(the value in the NORMDIST function should have read "7.8680" and not
"7.8800").

=1-NORMSDIST(7.8600) = 1.887e-15
=1-NORMSDIST(7.8680) = 1.776e-15 (corrected)
=1-NORMSDIST(7.874962586) = 1.776e-15
=1-NORMSDIST(7.874962587) = 0

Regards,
B. R. Ramachandran


"crapatmath" wrote:

Hi All,
I already posted this in the Worksheet Functions thread but I'm not sure if
that was the right place?

Anyway here is my question......
Why is
1-NORMSDIST(7.8) = 3.10862e-15
while
1-NORMSDIST(7.9) = 0

Is there a limit to how far out the Gaussian PDF curve you can go before
Excel rounds to zero?

Thanks

Barry