4.30. An internet service provider has two connection lines for its customers. Eighty percent of
customers are connected through Line I, and twenty percent are connected through Line II.
Line I has a Gamma connection time with parameters a = 3 and λ = 2 min-¹. Line II has
a Uniform(a, b) connection time with parameters a = 20 sec and b = 50 sec. Compute the
probability that it takes a randomly selected customer more than 30 seconds to connect to
the internet.