Index number of fuel = 100 + increase of 220% for the year 2015 = 320
Index number of rent for the year 2015 = \(\cfrac{6000}{4000} × 100\) = 150
Index number of miscellaneous expenses for the year
= 100 + (100 × 1.75) = 100 + 175 = 275
Percentage expenditure on miscellaneous expenses = 100-(40 + 18 + 12 + 20) = 100 – 90 = 10

Cost of living index number for the year 2015
\(I = \frac{ΣIW}{ΣW}\)
\(= \cfrac{19634.6}{100}\)
= 196.35
Interpretation: There is (196.35 – 100=) 96.35% increase in the cost of living expenditure of the year 2015 as compared to the base year.