Re: [gov1000-list] sample v. population confidence intervals

Mike, et al: My intepretation of the events in question is that you always should use the n-1 because you never know the actual population mean. However, on the homework, we were told (at least tonight we were told- it doesn't say this on the homework) to assume that we did know the population mean, and were working backwards. In that case, you can use the population sd. The difference seems to have to do with the presumption about what the population mean is. if you assume that your estimate is right (a false assumption, but the one we were supposed to use in the homework), then you can use n. otherwise, its n-1. However, i would note that i have never heard of anyone actually doing this, probably because the difference between n and n-1 is so small as to be irrelevant in general. So most people just round the n-1 to n, and forget about it. This is what i have learned in the past... best jason ----- Original Message ----- From: "Michael Richard Kellermann" <kellerm(a)fas.harvard.edu> To: <gov1000-list(a)fas.harvard.edu> Sent: Wednesday, September 24, 2003 10:39 PM Subject: [gov1000-list] sample v. population confidence intervals