The standard deviation is defined as the square root of the variance, so the variance is the same as the squared standard deviation.
mean
No. The average of the deviations, or mean deviation, will always be zero. The standard deviation is the average squared deviation which is usually non-zero.
zero
13.1 squared = 3.62
No, a standard deviation or variance does not have a negative sign. The reason for this is that the deviations from the mean are squared in the formula. Deviations are squared to get rid of signs. In Absolute mean deviation, sum of the deviations is taken ignoring the signs, but there is no justification for doing so. (deviations are not squared here)
No. It is defined to be the positive square root of ((the sum squared deviation divided by (the number of observations less one))
No. The square of a number is always positive, so the sum of several of them must also be positive.
Given a set of n scores, the variance is sum of the squared deviation divided by n or n-1. We divide by n for the population and n-1 for the sample.
No, you have it backwards, the standard deviation is the square root of the variance, so the variance is the standard deviation squared. Usually you find the variance first, as it is the average sum of squares of the distribution, and then find the standard deviation by squaring it.
A set of numbers will have a mean, which is defined as the sum of all the values divided by the number of values. Suppose this mean is m. For each of the values, the squared deviation is the square of the difference between that value and m. Algebraicly, if you have a set {x1, x2, x3, ... , xn}, whose mean is m, then the squared deviation from the mean for x1 is (x1 - m)2.
You cannot "solve" a mean squared deviation". You can calculate it or use it, but there is nothing to solve!
The standard deviation is defined as the square root of the variance, so the variance is the same as the squared standard deviation.
mean
No. The average of the deviations, or mean deviation, will always be zero. The standard deviation is the average squared deviation which is usually non-zero.
When the sum of a number plus 3 is squared, it is 11 more than the sum of the number plus 2 when squared.
zero