Probability Distribution and Mean, Variance and Expectation

Variable- characteristic or attribute that can assume different values.
Random Variable- a variable whose values are determined by chance.
Discrete Variables- values that can be counted.
Continuous Variable- obtain from data that can be measured rather than counted.


PROBABILITY DISTRIBUTION

• First requirement for a probability distribution: the sum of the probabilities of all events in the sample space must be equal to 1, that is SP(X)=1
• Second requirement for a probability distribution: the probability for each event is the sample space must be between or equal to 0 or 1.

G. Elio