Chapter 15 - Statistics

Example 2. The following table gives the distribution of expenditure of different familes on education. Find the mean expenditure on education of a family.

Expenditure (in Rs. )	Number o families
1000-1500	24
1500-2000	40
2000-2500	33
2500-3000	28
3000-3500	30
3500-4000	22
4000-5000	16
4500-5000	7

Solution:-

Expenditure (in Rs.)	No. of the families	xi		fi ui
1000-1500	24	1250	-3
1500-2000	40	1750	-2
2000=2500	33	2250	-1
2500-3000	28	2750=a	0	0
3000-3500	30	3250	1
3500-4000	22	3750	2
4000-4500	16	4250	3
4500-5000	7	4750	4

Here a = 2750, h = 500

Mean expenditure