RMS Function

The root mean square is the square root of the arithmetic mean of the squares of the values. If all the arguments are missing values, then the result is a missing value. Otherwise, the result is the root mean square of the non-missing values.

Let $n$ be the number of arguments with non-missing values, and let $x_1,x_2,\dots ,x_n$ be the values of those arguments. The root mean square is