The "mean" is the "average"
you're used to, where you add up all the numbers and then divide by the number of numbers.
"median" is the "middle" value in the list of numbers. To find the median,
your numbers have to be listed in numerical order, so you may have to rewrite your list first.
The "mode" is the value that occurs most often. If no number is repeated, then there
is no mode for the list.