# HP50g normal distribution function question

• February 27th 2011, 06:04 AM
Neverquit
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
• February 27th 2011, 07:19 AM
Neverquit
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).
• February 27th 2011, 07:55 AM
FernandoRevilla
Look at any normal distribution table, you'll inmediately find $k=1.72$ .
• February 27th 2011, 07:57 AM
Neverquit
Hi but I am trying to do it on my HP50g.

Regards,
Neverquit
• February 27th 2011, 08:06 AM
FernandoRevilla
Quote:

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 :)
• February 27th 2011, 11:08 AM
mr fantastic
Quote:

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.
• February 27th 2011, 11:32 AM
CaptainBlack
Quote:

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
• February 27th 2011, 09:34 PM
Neverquit
probability
Thanks Captain Black