MICROECONOMICS CH : 5 THEORY OF DEMAND — Economics STD 11 Commerce — Question

Define cost of living index numbers. Give its formulae.

Find out the standard deviation from the following data after finding mean:

Class lnterval:	0-10	10-20	20-30	30-40	40-50
Frequency:	8	13	16	8	5

Following table gives the distribution of companies according to the size of capital. Using step-deviation method, find out the mean size of the capital of a company:

Capital (in lacs)	Less than 5	Less than 10	Less than 15	Less than 20	Less than 25	Less than 30
No. of Companies	20	27	29	38	48	53

Briefly explain the published sources of secondary data.

Compare census and sampling method of conducting a survey. Which one is better and why

The existence of a large number of buyers and sellers means that each individual buyer and seller is very small compared to the size of the market. This means that no individual buyer or seller can influence the market by their size. Homogeneous products further mean that the product of each firm is identical. So a buyer can choose to buy from any firm in the market, and she gets the same product. Free entry and exit mean that it is easy for firms to enter the market, as well as to leave it.

1. Which of the following does not support the argument of perfectly competitive firm being a price taker?
(a) Large number of firms
(b) Sale of homogeneous products
(c) Price discrimination
(d) Price fixation by the industry

2. degree of product differentiation is found under perfect competition.
(a) Zero
(b) One
(c) Infinite
(d) None of these

3. Under perfect competition, demand curve of a firm is:
(a) perfectly elastic
(b) perfectly inelastic
(c) more elastic
(d) less elastic

4. A firm under perfect competition earns only normal profits in the short run. (True or False)

5. Read the following statements carefully and choose the correct alternative among those given below:
Statement 1: Perfectly competitive firms exercise partial control over price.
Statement 2: Product differentiation is widely practiced under perfect competition.
(a) Both the statements are true
(b) Both the statements are false
(c) Statement 1 is true and Statement 2 is false
(d) Statement 2 is true and Statement 1 is false

6. What is the shape of average revenue curve under perfect competition?

Draw the 'less-than' and 'more-than'ogive from the data given below:

Weekly Wages (in ₹)	Number of Workers
0-20	10
20-40	20
40-60	40
60-80	20
80-100	10

Calculate the index number for the period year 2008 to 2015, taking 2008 as base year:

Year (₹)	2008	2009	2010	2011	2012	2013	2014	2015
Price (₹)	75	50	65	60	72	90	75	70

Calculate Standard deviation from the following data:

Weight:	0-10	10-20	20-30	30-40	40-50
Frequency:	10	15	10	10	5

The following table gives the daily income of 10 workers in a factory. Find the arithmetic mean by using:

1. Direct method.
2. Assumed mean method.
3. Step-deviation method.

Workers	A	B	C	D	E	F	G	H	I	J
Daily Income (in ₹)	120	150	180	200	250	300	220	350	370	260