FIRST METHOD
From the frequency table, X stands for the number and F stands for the number of time that a particular number occur.
So, if we break the table down, we are going to have the following numbers:
1, 1, 2, 2, 3, 3, 3, 3, 3, 4.
The total number of occurrence = Addition of F = 10
Mean = [Summation of all occurrence] / Number of occurrence
Mean = [1+1+2+ 2+3 +3 +3 +3 +3 + 4] / 10 = 25 /10 = 2.5
Therefore, mean = 2.5
SECOND METHOD
Mean = [ 1*2] + [2* 2] + [3 * 5] + [4*1] / [2+ 2 + 5+ 1]
Mean = 2 + 4 + 15 + 4 / 10 = 25 / 10 2.5
Therefore, Mean = 2.5