Suppose we toss a fair coin repeatedly. We continue to do this until a tail is observed. Let X be the number of tosses required. Then X has:
A)a binomial distribution, with mean 0.5.
B)a binomial distribution, with mean 2.
C)a binomial distribution, with variance 0.707.
D)None of the answer options is correct.

Question

Quizplus · Accepted Answer

X follows a geometric distribution, not a binomial distribution, because it measures the number of trials until the first success (in this case, getting a tail). The mean and variance of a geometric distribution are not given in the options correctly for a fair coin toss scenario.

Suppose We Toss a Fair Coin Repeatedly