Discrete Distributions Means And Variance

Question 1

Discrete Uniform

Answer 1

Mean = E[X] = (a+b)/2

Variance = Var[X] = (b-a+1)^2/12

Question 2

Binomial

Answer 2

Mean = E[X] = np

Variance = Var[X] = np(1-p)

Question 3

Hypergeometric

Answer 3

Mean = E[X] = nm/N

Variance = Var[X] = N/A

Question 4

Geometric

Answer 4

Mean = E[X] = 1/p

Variance = Var[X] = (1-p)/p^2

Question 5

Negative Binomial

Answer 5

Mean = E[X] = r/p

Variance = Var[X] = r((1-p)/p^2)

Question 6

Poisson

Answer 6

Mean = E[X] = λ

Variance = Var[X] = λ