HP 20b statistical distributions

[Dieter]

(02-26-2015 06:13 PM)Dieter Wrote:  ...while the Normal CDF ("LTND") seems to work fine, the inverse is way off. For instance LTND^–1(0,9) returns 1,34479283373 instead of the expected 1,28155156554.

I just read HP's PDF #27 on "HP 20b probability distributions". Et voilà: page 5 shows an example where exactly this value – LTND^–1(0,9) – is calculated. Guess what, the result shown there is the same wrong 1,34 as mentioned above. I now remember I came across this PDF some time ago and wondered why this result was far off. So the error is even recorded in an "official" HP document.

Incredible... #-\

BTW, my 20b's firmware version is 11 25 2008. I wonder if there is a newer bugfixed version.

Dieter