The probability density function (p.d.f) is the function which allocates probabilities. Here is an example: Imagine you roll two tetrahedral dice (dice with 4 faces where the faces show 1, 2, 3 and 4 spots respectively). On each roll of the two dice.

A probability distribution is a function that describes the possible values of a For example, for a six-sided die, we would assign a probability of 1/6 to each of the If we rolled two six-sided dice, and let X be the sum, then X could take on any.

Example: Roll two dice . is called the frequency function or probability mass function. Properties of a discrete probability distribution.
A discrete random variable is a random variable that can take on any value from a discrete set of values. To find the probability of throwing a given sum k on several matching dice, you only need to know the number of faces n on each die and the number of dice thrown. Comments This is great, but it doesn't answer most important question: Why do I always fail my saving throws? Example: Rolling a Single Die. How many possible outcomes are there? The definition of this probability using an matthew 21 gives one important consequence for continuous random variables.