The mean of 6 observation is 60. If one of the number is excluded , then the mean becomes 45, find the excluded number
135
The mean of 6 observation is 60
Hence the total sum of 6 observation = 60 × 6 = 360
The mean of the 5 observation is 45
Hence the total sum of 5 obsevation = 45 × 5 = 225
The excluded number = Total sum of 6 observation - Total sum of 5 observation
= 360 - 225
=135