sample mean, variance and SD
On Nov 10, 2012, at 6:58 PM, Jim Lemon wrote:
On 11/11/2012 07:09 AM, Greg Snow wrote:
This is to all R-helpers (Sarah is just the one that I am replying to), Have we become a little too draconian on the "not a homework help list" issue? ...
As usual, a thoughtful comment on a problem that does not have a straightforward solution. The actual responses to obvious homework questions range from curt refusals to worked examples. I don't know the official status of the "no homework" policy if there is one.
The fourth entry (very close to the top) in the Posting Guide says: "<b>Basic statistics and classroom homework:</b> R-help is not intended for these."
My responses are guided by their expected utility. If the question appears to be asked by someone who has just gotten stuck on an esoteric quirk of R (and the extraction operators are a good example), I'll try to get them over the hump.
That's been my approach as well. I may simply offer: ?<func-name> ... but if they merely post an obvious homework problem with no effort visible I will either ignore it or point to the Posting Guide. Sometimes a preamble along the lines of "I tried to do this and cannot get academic support because the teacher is using SAS" will be sufficiently convincing.
In this particular case, parvez_200207 seems to have answered the question and not realized it.
I wondered whether parvez_200207 wanted to do the same procedure 1000 times and record the summary statistics each time.
Maybe this was due to something that parvez_200207 didn't even know was going on (e.g. a sink() was operating) or maybe it was just complete cluelessness. If I strongly suspected the former, I probably would have answered.
David Winsemius, MD Alameda, CA, USA