SESSION:3 Probability TopicsFormula Review – GU4L Leadership Institute

Session:3 Probability Topics

Formula Review

Introductory Business Statistics | Leadership Development – Micro-Learning Session

Rice University 2020 | Michael Laverty, Colorado State University Global Chris Littel, North Carolina State University| https://openstax.org/details/books/introductory-business-statistics

3.1 Terminology

A and B are events

P(S) = 1 where S is the sample space

0 ≤ P(A) ≤ 1

P(A $|$

$|$ B) = $\frac{P (A \cap B)}{P (B)}$

$\frac{� (� \cap �)}{� (�)}$

3.2 Independent and Mutually Exclusive Events

If $A$

$�$ and $B$

$�$ are independent, $P (A \cap B) = P (A) P (B),$

$� (� \cap �) = � (�) � (�),$ $P (A | B) = P (A)$

$� (� | �) = � (�)$ and $P (B | A) = P (B) .$

$� (� | �) = � (�) .$

If $A$

$�$ and $B$

$�$ are mutually exclusive, $P (A \cup B) = P (A) + P (B)$

$� (� \cup �) = � (�) + � (�)$ and $P (A \cap B) = 0 .$

$� (� \cap �) = 0 .$

3.3 Two Basic Rules of Probability

The multiplication rule: P(A $\cap$

$\cap$ B) = P(A $|$

$|$ B)P(B)

The addition rule: P(A $\cup$

$\cup$ B) = P(A) + P(B) – P(A $\cap$

$\cap$ B)