what is mean deviation and standard deviation
The mean deviation (also called the mean absolute deviation) is the mean of the absolute deviations of a set of data about the data's mean.For a sample size, the mean deviation is defined by. (1). where is the mean of the distribution. The mean deviation of a list of numbers is implemented in the Wolfram Language as.he mean deviation (also called the mean absolute deviation) is the mean of the absolute deviations of a set of data about the data's mean. For a sample size, the mean deviation is defined by.
The standard deviation of a random variable, statistical population, data set, or probability distribution is the square root of its variance. It is algebraically simpler, though in practice less robust, than the average absolute deviation.he variance is the mean of these values: and the population standard deviation is equal to the square root of the variance: This formula is valid only if the eight values with which we began form the complete population.