Question 40732
The mean or average tells you to add up numbers and divide the sum by the amount of numbers to get the midpoint. {{{a < b}}} is just a limitation to the available points to pick, but the average property tells you that is the way to find the midpoint.
Example:
<-----(-1)-----(0)-----(1)----->
(a + b)/2 = M
(-1 + 1)/2 = M
(0)/2 = M = 0