If a coin is tossed 2,000,000 times, what is the probability that it will come up exactly 1,000,000 times each heads and tails?

(In reply to Answer by K Sengupta)

By the problem, X~ Binomial (n, p), where:
n=2,000, 0000 and p=0.5 and:

Thus, P{X=1000000]
= comb(2000000, 1000000)/(2^2000000)
= 0.00056...

Consequently, the required probability is approximately  0.00056.

Posted by K Sengupta on 2007-05-28 13:46:44