3.33 / 3.33 ptsQuestion 20Arrivals to a bank automated teller machine (ATM) are distributed accordingto a Poisson distribution with a mean equal to three per 15 minutes.Determine the probability that in a given 15-minute segment no customerswill arrive at the ATM.
0.01240.0498Correct!0.03140.0281
3.33 / 3.33 ptsQuestion 21If a binomial distribution applies with a sample size ofn=20, find theprobability of 5 successes if the probability of a success is 0.40.
0 / 3.33 ptsQuestion 22The manager for State Bank and Trust has recently examined the credit cardaccount balances for the customers of her bank and found that 20% have anoutstanding balance at the credit card limit. Suppose the manager randomly

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Chap 5 Graded HW: OIS 2340-090 Summer 2015 Business Statistics
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selects 15 customers and finds 4 that have balances at the limit. Assume thatthe properties of the binomial distribution apply.What is the probability that 4 or fewer customers in the sample will havebalances at the limit of the credit card?
3.33 / 3.33 ptsQuestion 23Magic Valley Memorial Hospital administrators have recently received aninternal audit report that indicates that 15% of all patient bills contain anerror of one form or another. After spending considerable effort to improvethe hospitalʹs billing process, the administrators are convinced that thingshave improved. They believe that the new error rate is somewhere closer to0.05.Suppose that recently the hospital randomly sampled 10 patient bills andconducted a thorough study to determine whether an error exists. It found 3bills with errors. Assuming that managers are correct that they haveimproved the error rate to 0.05, what is the probability that they would find3 or more errors in a sample of 10 bills?

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Chap 5 Graded HW: OIS 2340-090 Summer 2015 Business Statistics
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3.33 / 3.33 pts
Question 24Given a binomial distribution withn=8 andp=0.40, obtain the standarddeviation.
1.386Correct!1.4651.9211.848
0 / 3.33 ptsQuestion 25The Weyerhauser Lumber Company headquartered in Tacoma, Washington,is one of the largest timber and wood product companies in the world.Weyerhauser manufactures plywood at one of its Oregon plants. Plywoodcontains minor imperfections that can be repaired with small ʺplugs.ʺ Onecustomer will accept plywood with a maximum of 3.5 plugs per sheet onaverage. Suppose a shipment was sent to this customer and when thecustomer inspected two sheets at random, 10 plugged defects were counted.What is the probability of observing 10 or more plugged defects if in fact the3.5 average per sheet is being satisfied?

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Chap 5 Graded HW: OIS 2340-090 Summer 2015 Business Statistics
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3.33 / 3.33 pts