HP Forums

Full Version: Statistics issue with NORMALD_CDF?
You're currently viewing a stripped down version of our content. View the full version with proper formatting.
I'm trying to run normal cumulative distribution functions in "Home" mode.

First, this seems to work fine in CAS:

normald_cdf(10, 0.2, 10.4) ==> 0.9772...

But when I try this in Home mode, I get:

10 Enter 0.2 Enter 10.4 Enter NORMALD_CDF() ==> 1

which is wrong...

However, the test case in help works fine:

0 ENTER 1 ENTER 2 ENTER NORMALD_CDF() ==> 0.9772...

which gives the same as in the CAS test case above because they both correspond to 2 sigma...

So am I doing something wrong in Home mode? Or is the mean value and standard deviation being treated as 0, 1 rather than 10, 0.2?

Thanks

-Jonathan
(03-23-2015 08:19 PM)Jonathan Cameron Wrote: [ -> ]I'm trying to run normal cumulative distribution functions in "Home" mode.
First, this seems to work fine in CAS:
normald_cdf(10, 0.2, 10.4) ==> 0.9772...
But when I try this in Home mode, I get:
10 Enter 0.2 Enter 10.4 Enter NORMALD_CDF() ==> 1
which is wrong...
...

hello Jonathan,
also by in Home (with RPN) it' wrong, but it's ok in Algebric mode and TextBook, so I think there is something not correct concerning RPN...

Salvo
(03-23-2015 08:19 PM)Jonathan Cameron Wrote: [ -> ]But when I try this in Home mode, I get:

10 Enter 0.2 Enter 10.4 Enter NORMALD_CDF() ==> 1

So am I doing something wrong in Home mode? Or is the mean value and standard deviation being treated as 0, 1 rather than 10, 0.2?

I think you need to tell it how many arguments you take off the stack, so please try

10 Enter 0.2 Enter 10.4 Enter NORMALD_CDF(3)

Cheers, Terje
(03-23-2015 08:43 PM)Terje Vallestad Wrote: [ -> ]
(03-23-2015 08:19 PM)Jonathan Cameron Wrote: [ -> ]But when I try this in Home mode, I get:

10 Enter 0.2 Enter 10.4 Enter NORMALD_CDF() ==> 1

So am I doing something wrong in Home mode? Or is the mean value and standard deviation being treated as 0, 1 rather than 10, 0.2?

I think you need to tell it how many arguments you take off the stack, so please try

10 Enter 0.2 Enter 10.4 Enter NORMALD_CDF(3)

Cheers, Terje

Thanks Terje!

I did not know you had to tell it how many arguments to process. It makes sense that the number of arguments is necessary since 1, 3, and 4 arguments all are legal but mean different things.

-Jonathan
Reference URL's