44. The probability that a call to an emergency help line is answered in less than 10 seconds is 0.8. Assume that the calls are independent of each other. Using the normal approximation for binomial with a correction for continuity, the probability that at least 75 of 100 calls are answered within 10 seconds is approximately _______ a) 0.8 b) 0.1313 c) 0.9154 d) 0.5235 e) 0.8687 45. Inquiries arrive at a record message device according to a Poisson process of rate 15 inquiries per minute. The probability that it takes more than 12 seconds for the first inquiry to arrive is approximately _________ a) 0.75 b) 0.05 c) 0.25 d) 0.27 e) 0.73

48.Incoming phone calls generally are thought to be Poisson distributed. If an operator averages 2.2 phone calls every 30 seconds, what is the expected (average) amount of time between calls (in seconds)?

a) 66 b) 30 c) 60 d) 13.64 e) 27.27

49. Incoming phone calls generally are thought to be Poisson distributed. If an operator averages 2.2 phone calls every 30 seconds, what is the probability that a minute or more would elapse between incoming calls?

a) 0.9877 b) 0.0123 c) 0.4877 d) 0.5000 e) 0.5123

50. Incoming phone calls generally are thought to be Poisson distributed. If an operator averages 2.2 phone calls every 30 seconds, what is the probability that at least two minutes would elapse between incoming calls?

a) 0.9998 b) 0.4998 c) 0.0002 d) 0.5000 e) 0.5002