2.7 Random Variables

Question 1

Formula for variance

Answer 1

E(x^2) - E(x)^2

Question 2

What is the bernoulli distribution

Answer 2

It is a complementary event (e.g. tossing a coin)
range of values {0, 1}
P(X = 1) = p
P(X = 0) = 1 - p

E(x) = p
var(x) = p(1 - p)

Question 3

What is formula for expected and variance values for a binomial distribution

Answer 3

E(x) = np
var(x) = np(1-p)

Question 4

What is p(X = k) for the poisson distribution?

Answer 4

(lamda^k)/k! * (e^-lamda)

lamda = np

Question 5

what is e(x) and var(x) for poisson distribution

Answer 5

both lamda