Question

The following table shows the income of farmers in a grape season. Find the mean of their income. 

Income (Thousand Rupees)	20 - 30	30 - 40	40 - 50	50 - 60	60 - 70	70 - 80
Farmers	10	11	15	16	18	14

Answer 1

Class (Income in thousand rupees)	Class Mark xi	Frequency (Number of farmers) fi	Class mark × Frequency xifi
20 - 30	25	10	250
30 - 40	35	11	385
40 - 50	45	15	675
50 - 60	55	16	880
60 - 70	65	18	1170
70 - 80	75	14	1050
		\[\sum_{} f_i = 84\]	\[\sum_{} x_i f_i = 4410\]

Mean = \[\frac{\sum_{} x_i f_i}{\sum_{} f_i}\]
= `4410/84`

= 52 . 5 thousand rupees

= 52500

Hence, the mean of the income is Rs 52500.