2. Arithmetic average: x =( 1/ number) * (sum of x numbers) (symbols can't be played, but it's cool).

3. Variance =( 1/ number) * (the square of the difference between each number and the arithmetic mean)

If the data is an integer, variance =( 1/ number) * (sum of squares of all numbers-number * square of arithmetic mean).

For example: variance = (1/3) * (1+2+3-3 * 2) = (1/3) * (1+4+9-6) = 8/3.

4. Standard deviation = arithmetic mean root of variance

That's all that matters.