Question

The following frequency distribution table shows the amount of aid given to 50 flood affected families. Find the mean of the amount of aid.

Amount of aid (Thousand rupees)	50 - 60	60 - 70	70 - 80	80 - 90	90 - 100
No. of families	7	13	20	6	4

Answer 1

Class (Amount of aid in thousand rupees)	Class Mark xi	Frequency (Number of families) fi	Class mark × Frequency xifi
50 - 60	55	7	385
60 - 70	65	13	845
70 - 80	75	20	1500
80 - 90	85	6	510
90 - 100	95	4	380
		`sum f_i ` = 50	`sum x_i f_i = 3620`

 

 Mean = `(sum x_i f_i )/(sum f_i)`

          `= 3620/50`

           = 72.4 thousand rupees 

           = Rs 72400

Hence, the mean of the amount of aid is Rs 72400.