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):}

Following is the pocket allowance of 10 students. Find out arithmetic

1.	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):}
Answer» Solution : The SUM of '+' deviations = + 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.