LibraryPirate

REVIEW QUESTIONS AND EXERCISES 131
REVIEW QUESTIONS AND EXERCISES
1. What is a discrete random variable Give three examples that are of interest to the health professional.
2. What is a continuous random variable Give three examples of interest to the health professional.
3. Define the probability distribution of a discrete random variable.
4. Define the probability distribution of a continuous random variable.
5. What is a cumulative probability distribution
6. What is a Bernoulli trial
7. Describe the binomial distribution.
8. Give an example of a random variable that you think follows a binomial distribution.
9. Describe the Poisson distribution.
10. Give an example of a random variable that you think is distributed according to the Poisson law.
11. Describe the normal distribution.
12. Describe the standard normal distribution and tell how it is used in statistics.
13. Give an example of a random variable that you think is, at least approximately, normally distributed.
14. Using the data of your answer to Question 13, demonstrate the use of the standard normal distribution
in answering probability questions related to the variable selected.
15. Kanjanarat et al. (A-12) estimate the rate of preventable adverse drug events (ADEs) in hospitals
to be 35.2 percent. Preventable ADEs typically result from inappropriate care or medication errors,
which include errors of commission and errors of omission. Suppose that 10 hospital patients experiencing
an ADE are chosen at random. Let p = .35, and calculate the probability that:
(a) Exactly seven of those drug events were preventable
(b) More than half of those drug events were preventable
(c) None of those drug events were preventable
(d) Between three and six inclusive were preventable
16. In a poll conducted by the Pew Research Center in 2003 (A-13), a national sample of adults answered
the following question, “All in all, do you strongly favor, favor, oppose, or strongly oppose . . . making
it legal for doctors to give terminally ill patients the means to end their lives” The results showed
that 43 percent of the sample subjects answered “strongly favor” or “favor” to this question. If 12
subjects represented by this sample are chosen at random, calculate the probability that:
(a) Exactly two of the respondents answer “strongly favor” or “favor”
(b) No more than two of the respondents answer “strongly favor” or “favor”
(c) Between five and nine inclusive answer “strongly favor” or “favor”
17. In a study by Thomas et al. (A-14) the Poisson distribution was used to model the number of
patients per month referred to an oncologist. The researchers use a rate of 15.8 patients per month
that are referred to the oncologist. Use Table C in the Appendix and a rate of 16 patients per month
to calculate the probability that in a month:
(a) Exactly 10 patients are referred to an oncologist
(b) Between five and 15 inclusive are referred to an oncologist