Answer to Question #155899 in Statistics and Probability for Benjamin

Question

For which of the following probability of distribution are the mean and variance equal? (a) Normal (b) Gamma (c) Poisson (d) Binomial

Answer 1

Poisson distribution

We have both the mean, variance are defined to λ. & PMF of Poisson defined to

PMF of P.D is = f ( k ) $= e^{-λ} \frac{ λx }{ x!}$

Where  

λ = parameter of the distribution