Joint Probability

Random variable

A random variable is a function that assigns a real number to each value in the sample space. This is produced as a result of a random experiment like tossing a coin or throwing a dice.

Example 1

When we flip a coin twice, there are four possible outcomes: both heads, heads and tails, tails and heads, or both tails. The value of x below represents the number of heads from each outcome of these four outcomes.:

Sample Space	x
HH	2
HT	1
TH	1
TT	0

Example 2

Random variable Y represents the number of times we roll “5” when rolling a six-sided dice six times. Therefore, the possible values of this random variable Y, can be anything from 0 (we never roll “5”) to6 (we roll “5” every time).

Joint probability

This refers to the Probability ...