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From | "Lachenbruch, Peter" <Peter.Lachenbruch@oregonstate.edu> |
To | "'statalist@hsphsun2.harvard.edu'" <statalist@hsphsun2.harvard.edu> |
Subject | RE: st: how to find the integral for a portion of a normal distribution. |
Date | Tue, 4 May 2010 09:43:37 -0700 |
This seems to be the expectation of x for x>c. I used integration by parts and got (DON'T TRUST ME HERE - I haven't done this for a while) Exp(-.5*((c-mu)/sigma)^2) + mu*P(x>c) It's simple enough that it feels right. Tony Peter A. Lachenbruch Department of Public Health Oregon State University Corvallis, OR 97330 Phone: 541-737-3832 FAX: 541-737-4001 -----Original Message----- From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Buzz Burhans Sent: Monday, May 03, 2010 8:59 PM To: statalist@hsphsun2.harvard.edu Subject: RE: st: how to find the integral for a portion of a normal distribution. Mike, thanks for your help. Let me try to clarify what I want. If I have a trial where average response was 2.05 liters, sd 1.74, What I want to find is the cumulative volume of all responses >= 1; and the cumulative volume of all responses <1 Is that any clearer? Thanks Buzz Burhans, Ph.D. Dairy-Tech Group So. Albany, VT / Twin Falls ID Phone: 802-755-6842 Cell: 208-320-0829 Fax VT: 802-755-6842 Fax ID: 208-735-1289 Email: buzzb3@earthlink.net -----Original Message----- From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Hollis,Michael E Sent: Monday, May 03, 2010 9:36 PM To: statalist@hsphsun2.harvard.edu Subject: Re: st: how to find the integral for a portion of a normal distribution. I may be missing something here, but can't you simply use the normal distribution with mean=proportion z >= some threshold, q=1-p and variance p(1-p)/n? No integration involved. As I said, I might be missing something! Sent from my iPhone On May 3, 2010, at 7:58 PM, "Buzz Burhans" <buzzb3@earthlink.net> wrote: > of the observations <=1 from * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/ * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/ * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/