6.2 DISCRETE PROBABILITY DISTRIBUTIONS Defn If a sample space contains a finite number of possibilities or an unending sequence with as many elements as there are whole numbers, it is called a discrete sample space. Defn A random variable defined over a discrete sample space is called a discrete random variable.Defn A table or formula listing all possible values that a discrete random variable can take on, along with the associated probabilities, is called a discrete probability distribution. Remark The probabilities associated with all possible values of a discrete random variable must sum to 1. Examples: 1. For Experiment No. 1, the discrete probability distributions of the random variables Xand Yare X 0 1 2 3 P(X=x) 1/8 3/8 3/8 1/8 Y -3 -1 1 3 P(Y=y) 1/8 3/8 3/8 1/8 2. Construct the discrete probability distribution for the random variable Mdefined in Experiment No. 2.