Standard deviation and normal distribution (Algebra 2 ...
www.mathplanet.com › education › algebra-2Standard deviation and normal distribution. Standard deviation is a widely used measurement of variability or diversity used in statistics and probability theory. It shows how much variation or "dispersion" there is from the "average" (mean, or expected value). A low standard deviation indicates that the data points tend to be very close to the mean, whereas high standard deviation indicates that the data is spread out over a large range of values.
Normal distribution - Wikipedia
https://en.wikipedia.org/wiki/Normal_distributionThe simplest case of a normal distribution is known as the standard normal distribution or unit normal distribution. This is a special case when and , and it is described by this probability density function (or density): The variable has a mean of 0 and a variance and standard deviation of 1. The density is has its peak at and inflection points at and .
The Standard Normal Distribution
sphweb.bumc.bu.edu › otlt › MPH-ModulesJul 24, 2016 · The standard normal distribution is a normal distribution with a mean of zero and standard deviation of 1. The standard normal distribution is centered at zero and the degree to which a given measurement deviates from the mean is given by the standard deviation. For the standard normal distribution, 68% of the observations lie within 1 standard deviation of the mean; 95% lie within two standard deviation of the mean; and 99.9% lie within 3 standard deviations of the mean.