Normal Distribution

Random variable

A variable with numeric values that can be determined from a random phenomenon

Discrete random variables

Random variables that have countable numbers of values, usually taking values like zero and positive integers

Continuous random variables

Random variables that are not integers but take values that lie in an interval

Normal distribution

A probability function of a continuous random variable

A normal distribution

The distribution is symmetrical with most of the data clustered around the centre close to the mean

A normal distribution

The probabilities for the data further from the mean taper off equally in both directions

the notation used for a continuous random variable X which has a normal distribution

Normal distribution function graphs have similar shapes,

their positions and the width of the graphs depend on their respective mean, and standard deviation

The shapes and positions of normal graphs

The larger the mean value, the more to the right the position of the graph

The shapes and positions of normal graphs

The height of the graph increases when the standard deviation value decreases if mean is kept constant