In the proof of Theorem 2 we determined the quantity E[X(X - 1)], called the second factorial moment. In general, the rth factorial moment of X is given by
![](https://test.transtutors.com/qimg/c7877b64-aca9-4ae6-a4b4-5563e561f458.png)
Express μ'2, μ'3, and μ'4 in terms of factorial moments. 1
Theorem 2
The mean and the variance of the binomial distribution are
![](https://test.transtutors.com/qimg/0b49630e-cfad-48f6-ab50-800fab2f7c2f.png)