The length of time of calls made to a support helpline follows an exponential distribution with an average duration of 50 minutes so that ? = 1/50 = 0.02. (Round your answer to four decimal places.) (a) What is the probability that a call to the helpline lasts less than 10 minutes? (b) What is the probability that a call to the helpline lasts more than 65 minutes? (c) What is the probability that a call lasts between 20 and 30 minutes? (d) Tchebysheff's Theorem says that the interval 50 ± 2(50) should contain at least 75% of the population. What is the actual probability that the call times lie in this interval?
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The average duration of calls is 50 minutes, so the parameter for the exponential distribution is λ = 1/50. Show more…
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