An enquiry into the budgets of the middle class families in a certain city gave the following information;
| Expenses on items | Food 35% | Fuel 10% | Clothing 20% | Rent 15% | Misc. 20% |
|---|---|---|---|---|---|
| Price (in Rs) in 2004 | 1500 | 250 | 750 | 300 | 400 |
| Price (in Rs) in 1995 | 1400 | 200 | 500 | 200 | 250 |
What is the cost of living index during the year 2004 as compared with 1995?
The cost of living index for the year 2004 as compared with 1995 is 134.50. This indicates that the cost of living has increased by 34.50% from 1995 to 2004.
Explanation
This question requires calculating the Consumer Price Index (CPI) using the weighted aggregative method. The formula CPI = ΣWR/ΣW is demonstrated in Example 4 of the textbook context. Students need to calculate the price relative (R) for each item by dividing current year price by base year price and multiplying by 100, then multiply by respective weights, sum them up, and divide by total weight.
Solution Steps
Step 1: Calculate Price Relative (R) for each item using formula R = (P₁/P₀) × 100
Food: R = (1500/1400) × 100 = 107.14
Fuel: R = (250/200) × 100 = 125
Clothing: R = (750/500) × 100 = 150
Rent: R = (300/200) × 100 = 150
Misc: R = (400/250) × 100 = 160
Step 2: Calculate WR (Weight × Price Relative) for each item
Food: WR = = 3750
Fuel: WR = = 1250
Clothing: WR = = 3000
Rent: WR = = 2250
Misc: WR = = 3200
Step 3: Sum all WR values
ΣWR = 3750 + 1250 + 3000 + 2250 + 3200 = 13450
Step 4: Apply CPI formula
CPI = ΣWR/ΣW = 13450/100 = 134.50