Characteristics of the normal distribution
1. The normal distribution is symmetric about the mean.
2. The total area under the curve = 1. Therefore due to symmetry,
the area to the left of the mean is .5 as is the area to the right of the
3. The mean, median and mode are all the same.
4. 68% of the area is within 1 standard deviation of the mean, 95%
within 2 and 99.8% within 3.
5. The normal distribution is determined by the parameters µ and
sigma, that is there is a different normal distribution for each value
of µ and sigma. Look at graphs on pages 228 and 229.
There are an infinite number of normal distributions.