Yes it is a homework problem, I included the whole question as I thought it would make it easier to explain however I am unsure of how to do the confidence interval part. As far as I am aware I have set up a matrix with my 100 samples of 100 and have calculated means. Do I need to set up a new matrix of these means and then do a confidence interval from there? Also when I searched 'confint' in R I am confused as to how to adapt it to my problem.
I am looking for the interval of each individual mean plus or minus 1.96/10 I wasnt aware of abs(x) and sum(means>0) so thankyou for pointing them out to me. Ben Bolker wrote: > > Rachel Keyes <rkeyes87 <at> hotmail.com> writes: > >> >> >> I am new to R and Im some trouble with the following question... Generate >> 100 > standard normal N(0,1) samples >> of size 100, X1(k),...,X100(k) where k=1,...,100 (The k is and indicie >> in > brackets) Calculate the sample >> mean for each sample. For each sample mean Xbark the 0.95-confidence >> interval > for the mean mew=0 is given >> by... Ik= ( Xbark plus or minus 1.96/10) Find the number of intervals >> such > that 0 does not belong to Ik. How >> many of them do you expect to see? Well so far I have come up with... >> N<-100; > Nsamp<-100 >> A<-matrix(rnorm(N*Nsamp,0,1),ncol=Nsamp) means<-apply(A,2,mean) However I >> have > no idea what I am >> doing and no idea if that even makes sense. Any help would be greatly > appreciated as I have no experience of >> statistical software whatsoever. Thanks in Advance. Rachel >> > > This sounds an awful lot like a homework problem. > Can you convince us not by giving us a little more context? > > I will say that you seem to have made a pretty good start. > A hint is that if you have a logical condition, > sum(condition) will count the number of cases. For > example, sum(means>0) will count the number of positive > means. ?abs and ?">" may help too. > > By the way, I think that's supposed to be "mu" and not "mew". > > Ben Bolker > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > > -- View this message in context: http://www.nabble.com/Confidence-Interval-tp21523397p21523829.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
