STDDEV: Standard deviation of a series of numbers

syntax: STDDEV(n, x1, x2, x3, ...) or
STDDEV(<filename>)

Returns the standard deviation of a series of numbers. Input can either be a series of numbers with the first argument specifying the number of elements in the series or a single argument specifying the name of the plain text file containing the series of numbers with each element in the file seperated by spaces or starting at a new line.