"Christian JAMMES" <[EMAIL PROTECTED]> wrote in message news:<[EMAIL PROTECTED]>...
> Assuming a set of measurements: > (m(i); sd(i)) with u(i) = measured value and u(i) = standard uncertainty > If one could propose the overall mean value mtot as being the weighted mean > value: > > mtot = sum(w.*m/sum(w)) with w(i)=1/u(i)^2, > > what the hell could be the overall variance vartot: > For any fixed weights w(i) and mutually independent measures m(i), var(sum(w(i)*m(i))/sum(w(i))) = sum(w(i)^2*var(m(i)))/(sum(w(i)))^2. . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
