Lesson 1 : Random Variables

random variable

a variable whose value varies and is determined by chance; it assigns a real number to each outcome of an experiment

chance variable

another term for random variable

sample space (S)

the set of all possible outcomes of an experiment

sample point

a single outcome in the sample space

experiment

a process or action that produces outcomes determined by chance

outcome

a result of a single trial of an experiment

possible values of a random variable

the unique numerical values assigned to outcomes in the sample space

assigning values

the process of giving numerical values to outcomes based on the definition of the random variable

tree diagram

a visual representation that shows all possible outcomes of an experiment

tabular method

a method of organizing outcomes and corresponding random variable values in a table

discrete random variable

a random variable that takes a countable number of values

countable

values that can be listed or counted

continuous random variable

a random variable that takes infinitely many values within a given range

measurable

values obtained through measurement

set-builder notation

a mathematical way of expressing a set using a rule or condition

discrete random variables examples

• Number of drivers violating traffic rules

• Number of PBA players selected

• Number of students in a class

• Number of cancer patients

continuous random variable examples

• Height of basketball players

• Speed of cars

• Weight of a child

• Time needed to run a race

counting

used for discrete random variables

measuring

used for continuous random variables

rule method

used for continuous random variables where listing outcomes is not possible