In article <[EMAIL PROTECTED]>, Jo <[EMAIL PROTECTED]> wrote: >The time that students spend at part time jobs per week is approximately >Normally distributed with standard deviation 8 hours. A random sample of 130 >students is taken and the sample mean is 11.4 hours. > >How do I find the 90% lower confidence limit for the true mean (mu)?
You don't, since the assumptions stated are false. It's not possible for the time to have a mean of around 11 and standard deviation of 8, since that would produce substantial numbers of students who work for a negative number of hours, which is clearly impossible. ---------------------------------------------------------------------------- Radford M. Neal [EMAIL PROTECTED] Dept. of Statistics and Dept. of Computer Science [EMAIL PROTECTED] University of Toronto http://www.cs.utoronto.ca/~radford ---------------------------------------------------------------------------- . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
