Examples of Combined Mean

Example 1:

Find out the combined mean when , N₁ = 6, , N₂ = 9.

Solution:

Combined Mean

Combined Mean

Combined Mean

Example 2:

Find out the combined mean when

Solution:

Combined Mean

Combined Mean

Combined Mean

Example 3:

Class A has 15 students with mean marks of 60, and Class B has 12 students with mean marks of 48. Calculate the combined mean.

Solution:

For Class A, , N₁ = 15

For Class B, , N₂ = 12

The required combined mean

Combined Mean

Example 4:

Assume that group 1 has 25 employees with an average salary of ₹82, group 2 has 32 employees with an average salary of ₹45, and group 3 has 77 employees. If the combined salary of the three groups is 70.86, find out the average salary of group 3.

Solution:

For Group 1, , N₁ = 25

For Group 2, , N₂ = 32

For Group 3, Assume average salary be and it is given that N₃ = 77

So, Combined Mean

9,495.24 = 3,490 + 77m

77m = 6005.24

m = ₹77.99 or ₹78

Hence, the average salary of group 3 is ₹78.