I'm trying to verify the calculation for the Inverse Cumulative Standard
Normal Distribution Function (also known as the Probit function) represented
by the Excel function NORMSINV( ).

For instance: The Excel function =NORMSINV(0.9626) returns 1.78.

Can someone show me a manual calculation for this? I'm currently digging
through the statistics books, but hoping for a quick-n-dirty solution.

Thanks,

- George