CH 23: Discrete random variables B: Discrete probability distributions A: Discrete random variables

23A: random variables Random variable – represents in number form the possible outcomes which could occur for some random experiment. Discrete random variable X has a distinct number of possible outcomes labeled: 𝒙 𝟏 , 𝒙 𝟐 , 𝒙 𝟑 , 𝒙 𝟒 , …, 𝒙 𝒏 to determine the number of discrete random variables we need to COUNT Examples: # of new cars sold each year by Ford, # of As on the End of Semester test in AP Calculus, etc Continuous random variable X could take possible values in some interval on the number line to determine the number of discrete random variables we need to MEASURE Examples: Heights of men which would all lie between 50<x<250cm, etc

23A: Probability Distributions For any random variable there is a corresponding probability distribution which describes the probability that the variable will take any particular value. Notation: Example:

23B: Discrete probability distributions CH 22: Probabilities may be assigned to events in a number of ways HOWEVER, if probabilities are assigned, the must satisfy the following rule:

23B: Discrete probability distribution

23B: Example

23B: Last Example