Create three columns on a piece of paper. Title first column as "Values," second column as "Frequency" and the third column as "Value x Frequency." The first column will have all the values of data. The second column will have all the frequency of each value and the third column will simply multiply each value with its associated frequency.
Add the values and frequency in the first two columns. As an example, add following values in the first column; 3,2,4,5,6 and 7. Similarly, add following frequency in the second column; 2,4,6,5,6 and 7. These two columns will look like this:
Values F
3 2
2 4
4 6
5 5
6 6
7 7
Calculate the third column by multiplying each value with the associated frequency. For example, for the first row, multiply 3 x 2, which equals 6. Similarly, multiply all values with its associated frequency. The third column of value x frequency will look like this:
Value x F
6
8
24
25
36
49
Add all frequency (the second column) and write down the total. In this example, total of all frequency is 30.
Add all value x frequency (the third column) and write down the total. In this example, the total of the third column is 148.
Divide total of value x frequency (third column) by the total of frequency (second column) and write down the result. In this example, divide 148 by 30 and the result is 4.933. This 4.933 is the weighted mean.