Answer to Question #305845 in Statistics and Probability for mondi

Question

A TELCO office has seven telephone lines. For the past months, the probability distribution of the random variable X which represents the number of busy lines per day, X={0, 1, 2, 3, 4, 5, 6, 7} P(X)={.02, .27, .06, .22, .15, .04, .08, .16}, what is the probability that the number of busy telephone lines in a day is fewer than six but at least one?

Answer 1

the probability that the number of busy telephone lines in a day is fewer than six but at least one:

P(1≤ X <6) = P(X=1) + P(X=2) + P(X=3) + P(X=4) + P(X=5)

= 0.27 + 0.06 + 0.22 + 0.15 + 0.04

= 0.74

Answer: 0.74