Geometric Random Variables

Question 1

P(x = k) in geometric random var

Answer 1

p(1-p)^k-1

Question 2

when are geometric random variables used

Answer 2

independent bernoulli trials to find probability required to obtain first success

Question 3

expected value in geometric random variable

Answer 3

E(X) = 1/p

Question 4

variance in geometric random variable

Answer 4

var(X) = (1-p)/(p^2)

Question 5

a product has a 3% defective rate

what is the probability of the first defective product occurs on the 5th item

Answer 5

(1-0.03)^5-1 * 0.03