On 21 Jan 2002 08:55:21 -0800, [EMAIL PROTECTED] (Scheltema, Karen) wrote:
> I have 2 independent samples and the standard errors and n's associated with > each of them. If a and b are constants, what is the formula for the 95% > confidence interval for > (a(Xbar1)+b(xbar2))? > Var(A+B) = Var(A) + Var(B) for A,B independent; and Var(kA) = k^2 Var(A) Right? The SE is the SD of the mean, so you have the terms you need. -- Rich Ulrich, [EMAIL PROTECTED] http://www.pitt.edu/~wpilib/index.html ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at http://jse.stat.ncsu.edu/ =================================================================
