1
$\begingroup$

This is exercise 1.23 from Casella and Berger Statistical inference.

Two people each toss a fair coin $n$ times. Find the probability that they will toss the same number of heads.

My reasoning is that the probability of the two sequences of tosses being exactly the same is $(1/4)^n$ now we need to see in how many ways can we permute these two sequences. But I am a bit stuck on how to proceed. How should I do?

$\endgroup$
4
  • 3
    $\begingroup$ "they will lose the same number of heads"??? $\endgroup$
    – Řídící
    Commented Feb 23, 2016 at 19:43
  • 1
    $\begingroup$ "the probability of the two sequences of tosses being exactly the same is $(1/4)^n$? Why not $(1/2)^n$? $\endgroup$
    – David G. Stork
    Commented Feb 23, 2016 at 19:44
  • 5
    $\begingroup$ Duplicate: math.stackexchange.com/q/83489/56801 $\endgroup$
    – Řídící
    Commented Feb 23, 2016 at 19:45
  • $\begingroup$ @KinnisalMountainChicken Oh dear... I edited. $\endgroup$
    – Monolite
    Commented Feb 23, 2016 at 19:46

0

Reset to default

Browse other questions tagged .