The Total solution for NCERT class 6-12
Daily expenditure(in c)
100-150
150-200
200-250
250-300
300-350
Number of households
4
5
12
2
Solution:
Find the midpoint of the given interval usingthe formula.
Midpoint (xi) = (upper limit +lower limit)/2
Let is assume the mean (A) = 225
Class size (h) = 50
Class Interval
Number of households (fi)
Mid-point (xi)
di = xi – A
ui = di/50
fiui
125
-100
-2
-8
175
-50
-1
-5
225
0
275
50
1
325
100
Sum fi = 25
Sum fiui = -7
Mean = x̄ = A +h∑fiui /∑fi
=225+50(-7/25)
= 225-14
= 211
Therefore, the mean daily expenditure on foodis 211