Characteristics of every normal distribution

1. Mean is always at the exact center.
2. Probability under entire curve must add up to 1.000 or 100% where 50% of the probability is to the right of the mean and 50% of the probability is to the left of the mean.
3. Probabilities associated with a normal distribution are calculated as areas under curve y=P(X) usually between two vertical straight lines.

In the last chapter we studied the Binomial and Poisson Distributions. These are famous distributions with a discrete random variable.

Now we go on to the Normal Distributions which have continuous random variables. The Normal curve is, in fact, the most famous or infamous distribution because it is also known as the "bell curve". It has a bell-shape and distributes probabilities symmetrically about the center which is the mean of the distribution.

Mathematical nature of the normal distribution:

General normal distribution formula is:

This formula is not to be memorized for this introductory course. The reason for its existence is that you may program it into Microsoft Excel or other software and get exact theoritical calculations for your normal distribution.