ABSTRACT
This chapter introduces the concept of a probability distribution. Probability mass function, cumulative distribution function, random variables (discrete and continuous), and a Bernoulli trial are covered. This chapter focuses on discrete random variables and covers two discrete probability distributions (binomial and Poisson) in detail. Measures of location and spread for both distributions are discussed. Readers learn how to apply the binomial and Poisson distributions to address public health problems that lend themselves to a probabilistic framework, allowing for experiential learning. Factorials, permutations, and combinations are also briefly discussed to provide the necessary mathematical foundation for the binomial distribution. The Euler number is briefly discussed to provide the necessary mathematical foundation for the Poisson distribution. Concepts are discussed in an epidemiologic framework (longitudinal data, person years). Readers are introduced to the use of statistical tables (Appendix Table A.1 and Table A.2) to calculate probabilities and are provided with statistical software code (SAS and Stata) related to the binomial and Poisson distributions.
