Twelve people: are given two identical speakers to listen to for differences, if any. Suppose that these people answered by guessing only. Find the probability that three people claim to have heard a difference between the two speakers.

Question

kropot72 · Answer

The probability that a person will claim to have heard a difference is 0.5. The binomial distribution applies, so we have:
$$P(3\ out\ of\ 12\ claim\ a\ difference)=12C3\times(0.5)^{12}=you\ can\ calculate$$

anonymous · Answer

is the ans = 5.3%

kropot72 · Answer

That is not quite the answer that I get.

kropot72 · Answer

12C3 = 220
0.5^12 = 1/4096.
So we have: 220/4096 = ?

anonymous · Answer

0.053

kropot72 · Answer

Not quite. It is 0.0537 which rounds to 0.054.