The mean is the average number from the group of numbers.
In this case, the average of the numbers 2, 4, 0, 3, 4, 1, 3, 1, 1, 5 is 2.4.
This is discovered by adding all the numbers together (which in this case is 24) and dividing that number by the amount of numbers in the group (in this case it's 10).
24 ÷ 10 = 2.4
Therefore the mean is 2.4.