The image above represents P(A or B).

To compute for P(A or B), four essential parameters are needed and these parameters are **x _{A}, N_{A}, x_{B}** and

**N**.

_{B}The formula for calculating P(A or B):

**P(A or B) = P(A) + P(B)**

Where;

**P(A)** = ^{xA} ⁄ _{N}_{A}

**P(B)** = ^{xB} ⁄ _{N}_{B}

Let’s solve an example;

Find the P(A or B) when x_{A} is 9, N_{A} is 11, x_{B} is 6 and N_{B} is 12.

This implies that;

x_{A} = 9

N_{A} = 11

x_{B} = 6

N_{B} = 12

**P(A or B) = P(A) + P(B)**

P(A or B) = ^{xA} ⁄ _{N}_{A} + ^{xB} ⁄ _{N}_{B}

P(A or B) = ^{9} ⁄ _{11} + ^{6} ⁄ _{12}

P(A or B) = ^{9(12) + 6(11)} ⁄ _{(11)(12)}

P(A or B) = ^{108 + 66} ⁄ _{132}

P(A or B) = ^{174} ⁄ _{132}

Dividing the numerator and denominator by **6**

P(A or B) = ^{29} ⁄ _{22}

P(A or B) = 1.318

Therefore, the **P(A or B) **is **1.318.**

Continue reading How to Calculate and Solve for P(A or B) | Probability