The Math Forum

Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Math Forum » Discussions » sci.math.* » sci.stat.math

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: Probability of selecting {n1,n2} from N tickets
Replies: 14   Last Post: Sep 25, 2012 1:34 AM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]

Posts: 517
Registered: 2/23/10
Probability of selecting {n1,n2} from N tickets
Posted: Sep 23, 2012 1:59 AM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

In an example of the likelihood function,
describes an experiment in which two tickets are chosen from N tickets
numbered from n1 to nN. Given integers n1 and n2, with n2>n1, the
probability of selecting {n1,n2} is given as 1/(N choose 2). But
there are N ways to choose n1, and N-1 ways to choose n2; hence, there
are N(N-1) ways to choose {n1,n2} should be N(N-1), which is certainly
not (N choose 2). What am I missing?

Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© The Math Forum at NCTM 1994-2018. All Rights Reserved.