Random Variable and Probability Distribution Flashcards
Sample Space
The set of all possible outcomes of an experiment.
Random Variable
a. A result of a chance event that you can measure or count.
b. A numerical quantity that is assigned to the outcome of an experiment.
c. A variable that assumes numerical values associated with the events of an experiment
d. A quantitative variable which values depends on change.
e. A function that associates a real number to each element in the sample space.
Types of Random Variable
a. Discrete Random Variable
b. Continuous Random Variable
Discrete Random Variable
Has countable number of values (count).
Continuous Random Variable
Has infinite number of possible values (measure).
Steps to Get The Value of Random Variable
a. Write the sample space.
b. Determine the values of random variable for each outcome.
c. Write the conclusion.
Permutation
Way of calculating the number of ways a particular set can be arranged.
Permutation Formula
nPr = n!/(n-r)!
Tree Diagram
a. Display all the possible outcomes of an event.
b. Each branch in a tree diagram represents a possible outcome.
Steps to Get the Probability Distribution
a.Determine the number of possible outcomes.
b. Determine the sample space.
c. Determine the value of the random variable for each outcome.
d. Make a probability distribution.
Formula for Probability
a. Probability = number of favorable outcomes/number of possible outcomes
b. Probability = frequency / number of possible outcomes
Probability Distribution
A table showing all the possible values of a discrete random variable together with their corresponding probabilities.
Properties of a Probability Distribution
a. Probabilities have a value which ranges from 0 to 1.
b. The sum of the probabilities is equal to 1.
