Date: Sun, 27 Jun 1999 18:02:28 -0400
Reply-To: "P. Adam Kelly" <pkelly@GARNET.ACNS.FSU.EDU>
Sender: "SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU>
From: "P. Adam Kelly" <pkelly@GARNET.ACNS.FSU.EDU>
Greetings, I have a question that, I hope, has an easy answer (I just can't
remember how it's done!):
I have a pool of 70 test items, only two of which I'm interested in. My
(computerized) test system administers 20 items out of the pool of 70,
selected at random, to a given test-taker. What is the probability that the
test-taker will see at least one of the two items of interest?
Does it have to do with "n choose k," or what?
Thanks for any replies!
P. Adam Kelly
Ph.D. Candidate, Measurement & Statistics
Dept. of Educational Research
Florida State University
Tallahassee, FL 32306-4453