Probability rules, Mathematics

Probability Rules

A probability is a number assigned to the occurrence of an event in a sample space. Probability measures must satisfy three rules. If A is an event with probability denoted by P(A), then the following rules hold:

Rule 1

The probability of the entire sample space S is 1, i.e. P(S) = 1.

29_probability rules.png

Area of sample space rectangle = 1. An event A is represented within the rectangle. Minimum possible area of A is 0 and maximum possible area is 1.

Rule 2

The probability of the event A must be greater than or equal to 0 and less than or equal to 1 or 100%, i.e. 0 < P(A) < 1. This rule says that probabilities cannot be negative and as the probability of the sample space is 1, the probability of an event contained in the sample space should be less than or equal to 1.

Rule 3

If A and B are mutually exclusive events, then the probability of (A or B) is equal to the sum of the probabilities of A and B.

P(A or B) =  P (A) + P (B) because P (A and B) = 0 as A and B are mutually exclusive.

Mutually exclusive events are those which do not overlap when represented in Venn diagrams.

1844_probability rules1.png

A & B are mutually exclusive events

C and D are not mutually exclusive events

Two events A and B are mutually exclusive if the occurrence of one implies the non-occurrence of the other. Hence obtaining a head on tossing a coin and obtaining a tail are mutually exclusive events.

Posted Date: 9/14/2012 4:25:18 AM | Location : United States







Related Discussions:- Probability rules, Assignment Help, Ask Question on Probability rules, Get Answer, Expert's Help, Probability rules Discussions

Write discussion on Probability rules
Your posts are moderated
Related Questions
How do you solve (17+w)^2 + w^2 = (25+w)^2

When there are 4 dots how many chords are they

what is the value of integration limit n-> infinity [n!/n to the power n]to the power 1/n Solution)  limit n-->inf.    [1 + (n!-n^n)/n^n]^1/n = e^ limit n-->inf.    {(n!-n^n)

Indeterminate forms Limits we specified methods for dealing with the following limits. In the first limit if we plugged in x = 4 we would get 0/0 & in the second limit

Example of Fractional Equations: Example: Solve the fractional equation (3x +8)/x +5 =0 Solution: Multiply both sides of the equation by the LCD (x). (x) ((3x

Explain the Common Forms of Linear Equations ? An equation whose graph is a line is called a linear equation. Here are listed some special forms of linear equations. Why should

5 hockey pucks and three hockey sticks cost $23. 5 hockey pucks and 1 hockey stick cost $20. How much does 1 hockey puck cost?

Example of Fractional Equations: Example: Solve the fractional equation (3x +8)/x +5 =0 Solution: Multiply both sides of the equation by the LCD (x). (x) ((3x

the radii of circular base of right circular cylinder and cone are in the ratio of 3:4 and their height are in the ratio of the 2:3 what is the ratio of their volume?

Where can I find sample questions of Unitary Method for kids to practice? I need  Unitary Method  study material if availbale here on website, i found there is very useful material