Exercise 2 y 1 second is equal to 0.1. Assume that customers arrive in a random
ID: 3065904 • Letter: E
Question
Exercise 2 y 1 second is equal to 0.1. Assume that customers arrive in a random stream and hence that an arrival in any 1 second is independent of all others. 1. Find the probability that the first arrival will occur during the thind 1- second interval. 2. Find the probability that the first arrival will not occur until at least the fourteenth 1-second interval. Exercise 2 The number of times that an individual contracts a cold in a given year is a Poisson random uariable with parameter = 5 . Suppose a new drug has just been marketed that reduces the Poisson parameter to A 2 for 75 percent of population. For the other 25 percent of the population the drug has no appreciable effect on colds. If an individual tries the drug for a year and has 2 colds in that time, how likely is it that the drug is beneficial for him or her? Exercise 3 The number of bacteria colonies of a certain type in samples of polluted water averages 2 per cubic centimeter. 1. If four 1-cubic-centimeters samples are independently selected from this water, find the probability that at least one sample will contain one or more bacteria colonies. 2. How many 1-cubic centimeter samples should be selected in order to haveExplanation / Answer
P(2 colds) =P(appreciable effect and 2 colds+not beneficial effect and 2 colds)
=0.75*e-2*22/2! +0.25*e-5*52/2! =0.75*0.2707+0.25*0.0842 =0.2241
therefore P(drug is beneficiail|2 colds) =P(appreciable effect and 2 colds)/P(2 colds)=0.75*0.2707/0.2241
=0.9060
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.