possibly you could use kid per candy, number of trickery treaters or something
you could explain lets say over the holidays Miss. So and So's class's kids got an average of around 4-6 Christmas presents while Miss. Mary Sue's class had kids with 2 presents and kids with 12, since the range between 2-12 is bigger it had a greater standard of deviation
(hopefully this helps and I am not overcomplicating or incorrecting the standard of deviation, good luck)
Reasoning: you would need to divide 492 by 3 to get the number of sprites seeing that the sandwiches are 3 times as much as the amount of sprites sold.
