Bar and bat mitzvah mean, literally, son and daughter of the commandment.. Bat mitzvah is Hebrew, while bar mitzvah, historically a much earlier ceremony, is Aramaic. The word bar is the Aramaic equivalent of the Hebrew ben (son of) .
In math, the mean is the average of a set of numbers. To determine the mean, add all numbers in a set and take this answer and divide it by how many numbers are in the set. Continue Reading.
The arithmetic mean is just the average, the value that is the sum of all values, divided by their number. This is what is most often referred to as mean. The geometric mean is the root of the product of all values.