Showing 11 to 20 of 1246 Questions
  • The probability that a patient recovers from a delicate heart operation is 0.9. What is the probability that exactly 5 of the next 7 patients having this operation survive?

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    194
  • A traffic control engineer reports that. 75% of the vehicles passing through a checkpoint are from within the state. What is the probability that fewer than 4 of the next 9 vehicles arc from out of state?

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    378
  • A study examined national attitudes about antidepressants. The study revealed that approximately 70% believe "antidepressants do not really cure anything they just cover up the real trouble." According to this study, what is the probability that at least 3 of the next 5 people selected at random will be of this opinion?

    2
    256
  • It is known that the percentage of wins for the Chicago Bulls basketball team going into the playoffs for the 1996-97 season was 87.7. Round the 87.7 to 90 in order to use Table A.1(a) What is the probability that the Bulls will sweep (4-0) in the initial best-of-7 playoff series?(b) What is the probability that the Bulls would tain the i

    1
    472
  • It is known that 60% of mice inoculated with a serum are protected from a certain disease. If 5 mice are inoculated, find the probability that(a) None contracts the disease;(b) Fewer than 2 contract the disease;(c) More than 3 contract the disease.

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    336
  • Suppose that airplane engines operate independently and fail with probability equal to 0.4. Assuming that a plane makes a safe flight if at least one-half of its engines run, determine whether a 4-engine plane or a 2-engine plane has the higher probability- for a successful flight.

    0
    511
  • If X represents the number of people in Exercise 5.13 who believe that antidepressants do not cure but only cover up the real problem, find the mean and variance of X when 5 people are selected at random and then use Chebyshev's theorem to interpret the interval μ ± 2a.

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    312
  • (a) In Exercise 5.9, how many of the 15 trucks would you expect to have blowouts?(b) According to Chebyshev's theorem, there is a probability of at least 3/4 that the number of trucks among the next 15 that have blowouts will fall in what interval?

    1
    559
  • As a student drives to school, he encounters a traffic signal. This traffic signal stays green for 35 seconds, yellow for 5 seconds, and red for 60 seconds. Assume that the student goes to school each weekday between 8:00 and 8:30. Let X1 be the number of times he encounters a green light, X2 be the number of times he encounters a yellow

    1
    419
  • According to USA Today (March 18, 1997), of 4 million workers in the general workforce, 0.8% tested positive for drugs. Of those testing positive, 22.5% were cocaine users and 54.4% marijuana users.(a) What is the probability that of 10 workers testing positive, 2 are cocaine users, 0 marijuana users, and 3 users of other drugs?(b) What i

    2
    503