# Thread: HP50g normal distribution function question

1. ## HP50g normal distribution function question

Hi ,

I just got a new HP50g and not sure how to solve for k.

Given P(X<k)=0.9573 .....(normal distribution)

Eg. using UTPN function for P(X<1)=0.8413:

UTPN(0,1,1)=0.1587 (ie the upper tail)

So 1-0.1587=0.8413 (ie lower tail)

Any help would be appreciated.

Neverquit

2. ## how to solve for k in normal distribution?

Hi

how do I solve this?

P(X<k)=0.9573

Mean =0
SD=1

Best regards,

Neverquit

Moderator edit: Moved from Probability and Statistics subforum (see post #3).

3. Look at any normal distribution table, you'll inmediately find $k=1.72$ .

4. Hi but I am trying to do it on my HP50g.

Regards,
Neverquit

5. Originally Posted by Neverquit
Hi but I am trying to do it on my HP50g.
In that case, I can't help you. HP50g is not a friend of mine

6. Originally Posted by Neverquit
Hi but I am trying to do it on my HP50g.

Regards,
Neverquit
In the first instance you either go to the manual (which no doubt will be available for download on the HP website) or ask your instructor.

7. Originally Posted by Neverquit
Hi

how do I solve this?

P(X<k)=0.9573

Mean =0
SD=1

Best regards,

Neverquit

Moderator edit: Moved from Probability and Statistics subforum (see post #3).
You want to solve the equation:

UTPT(0,1,x)=0.0427

You can do this by trial and error, or look at using the numerical equation solver described in chapter 6 of the manual.

To get you started UTPT(0,1,1.7)~=0.0445655, and UTPT(0,1,1.8)~= 0.0359303, so the required solution is in the interval (1.7,1.8)

CB

8. ## probability

Thanks Captain Black