Following is the pocket allowance of 10 students. Find out arithmetic mean using Short-cut Method.
`{:("Pocket Allowance(Rs.)",15,20,30,22,25,18,40,50,55,65):}`

Explanation

The sum of '+' deviatios = + 50
The sum of '-' deviations = - 110
The net sum of deviations, `sum d =-110+ 50 = -60`
Dividing the aggregate of deviations `(sum d)` by the number of
items (N), ` (sum d)/N =(-60)/10 = - 6`
Substituting this value of` (sum d)/n`in the following formula:
` barX = A+(sum d)/N `
We have,
`barX = 40 +(-) 6`
=40-6
=34
Arithmetic Mean = Rs. 34.