# Understanding standard deviation

hello

To increase my knowledge about stdev first: what happens to the result when values, equal to zero in the range (column), are included in calculating this range' stdev ?

Use as example a spreadsheet of money prize of a lottery. I calculated the average, the highest and lowest output of full year span of winnings. Some contests didn't have winner, so this zero is related to my first paragraph. Then I am trying to read this amount in stdev cell, which it's bigger(1) than the average output. How I comprehend is the stdev + average = the higher dispersion; and average - stdev = the lower dispersion, which is negative because of (1)!?

How is it possible? Why it gets bigger than average?

here are my stdev cell write out:

=stdev(if(F2:F1879<>0; F2:F1879))

and, with different result, might be incorrect:

=stdev(if(countif(F2:F1879;"<>0");F2:F1879))