The mean of numbers is . If one number is excluded, their mean is . Find the excluded number.
Step 1: Find the value of sum of terms
Given, the mean of five numbers items is .
Step 2: Find the new value of sum of terms, if one of the numbers is excluded.
Let excluded number
Step 3: Find the excluded number.
Given, the mean of the remaining numbers is . Which means the mean of four numbers is .
I.e.,
Hence, the value of excluded number is .