Chapter 6: Probability Distributions

Abstract

In Chapter 6, you will learn how to use R for several important probability distributions. We cover the binomial distribution, the Poisson distribution, the normal distribution, the t distribution, the F distribution, and the chi-square distribution. R uses a standardized method for naming the functions associated with each of these, so that it is easy to remember them. We use the letters d (for density), p (for probability), q (for quantile), and r (for random) to preface the function, so for the normal distribution, dnorm returns the density, pnorm returns the probability associated with an area under the curve, qnorm returns the score associated with a given probability, and rnorm produces the desired number of randomly generated scores from a normal distribution with a given mean and standard deviation.