1. Find Cost of living Index number by the Aggregate expenditure method

Item	Quantity	Price0	Price1
A	35	16	18
B	25	40	45
C	20	60	120
D	10	80	90
E	20	30	45
F	15	28	35

Solution:
Aggregate expenditure method :

Item	Quantity `q_0`	Price `p_0`	Price `p_1`	`p_0q_0`	`p_1q_0`
A	35	16	18	560	630
B	25	40	45	1000	1125
C	20	60	120	1200	2400
D	10	80	90	800	900
E	20	30	45	600	900
F	15	28	35	420	525
---	---	---	---	---	---
Total				`sum p_0q_0=4580`	`sum p_1q_0=6480`

Consumer price index number by Aggregate expenditure method

`I_L=(sum p_1q_0)/(sum p_0q_0) xx 100`

`=(6480)/(4580) xx 100`

`=141.48`

Thus, there is a rise of `(141.48-100)=41.48%` in Aggregate expenditure

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2. Find Cost of living Index number by the Aggregate expenditure method

Item	Quantity	Price0	Price1
A	40	160	200
B	25	400	600
C	5	50	70
D	20	10	18
E	10	2	3

Solution:
Aggregate expenditure method :

Item	Quantity `q_0`	Price `p_0`	Price `p_1`	`p_0q_0`	`p_1q_0`
A	40	160	200	6400	8000
B	25	400	600	10000	15000
C	5	50	70	250	350
D	20	10	18	200	360
E	10	2	3	20	30
---	---	---	---	---	---
Total				`sum p_0q_0=16870`	`sum p_1q_0=23740`

Consumer price index number by Aggregate expenditure method

`I_L=(sum p_1q_0)/(sum p_0q_0) xx 100`

`=(23740)/(16870) xx 100`

`=140.72`

Thus, there is a rise of `(140.72-100)=40.72%` in Aggregate expenditure

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3. Find Cost of living Index number by the Aggregate expenditure method

Item	Quantity	Price0	Price1
A	40	2	2.50
B	20	3	3.25
C	10	1.5	1.75

Solution:
Aggregate expenditure method :

Item	Quantity `q_0`	Price `p_0`	Price `p_1`	`p_0q_0`	`p_1q_0`
A	40	2	2.5	80	100
B	20	3	3.25	60	65
C	10	1.5	1.75	15	17.5
---	---	---	---	---	---
Total				`sum p_0q_0=155`	`sum p_1q_0=182.5`

Consumer price index number by Aggregate expenditure method

`I_L=(sum p_1q_0)/(sum p_0q_0) xx 100`

`=(182.5)/(155) xx 100`

`=117.74`

Thus, there is a rise of `(117.74-100)=17.74%` in Aggregate expenditure

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