An index number is a statistical device for measuring changes in the magnitude of a group of related variables.

Features of Index Number

1. Index numbers are expressed in terms of percentages. However, percentage sign (%) is never used.
2. Index numbers are relative measurement of group of data.
3. Index numbers offer a precise measurement of the quantitative change in the concerned variables over time.
4. Index number show changes in terms of averages.
5. They are expressed in numbers.
6. Index number facilitates the comparative study over different time period.

Firm. A firm is a single producing unit which produces goods and services for sale. Its main objective is to earn maximum profit.

Industry. An industry is an aggregate of all the firms producing the same product or interrelated product Alternatively, all the firms producing and selling the same or differentiated products of close substitutes are collectively known as an industry. For instance, firms manufacturing shoes will be collectively called shoe industry. Clearly a firm is a part of an industry.
Price determination. (Industry price-maker and firm price-taker). Under perfect competition, price of a commodity is determined by the equilibrium between market demand and market supply of the whole industry. So, the industry is called the price-maker. Here demand and supply represent total demand and total supply of industry. No individual firm can influence the price because its share in total supply is insignificant. Every firm has to accept the given price and adjust its level of output. It has no option but to sell the product at a price determined at industry level. If is because of this reason that firm is said to be price-taker and industry, the price-maker. This price is also called equilibrium price, because at this price quantity demanded is equal to quantity supplied. This can be illustrated with the help of the following demand and supply schedule and diagram of the industry:

A budget constraint represents all the combinations of goods and services that a consumer may purchase given current prices within his or her given income. Consumer theory uses the concepts of a budget constraint and a preference map to analyze consumer choices

An Economics tutor answered. Slope of a budget line is the "price ratio" of the two goods. ... Since the slope is constant we will get a straight line. The only case where a budget line may be non linear is the case of kinked constraints.

Univariate Frequency Distribution

1. When data is classified on the basis of single variable, the distribution is known as univariate frequency distribution.
2. It aims to make description about the particular variable.
3. It is also known as one-way frequency distribution.
4. Ex : Height of students in a class.

Bivariate Frequency Distribution :

1. When the data is classified on the basis of two variables, the distribution is known as bivariate frequency distribution.
2. It aims to determine the empirical relationship between the two variables.
3. It is also known as two-way frequency distribution.
4. Ex : Height and weight of students in a class.

UTILITY - Utility refers to the amount of satisfaction derived from the consumption of the unit of the product.

TOTAL UTILITY - Total utility refers to the total amount of satisfaction obtained from the consumption of number of products.

MARGINAL UTILITY - Marginal utility is the amount of satisfaction which is derived from the consumption of every additional unit.

Difference between Total Utility and Marginal Utility.

when TU decrease, MU increases.

when TU becomes zero, MU become stagnant.

when TU becomes negative, MU falls.

Total utility talks about the whole other hand's marginal utility talk about the single unit.

1. Slopes downwards to the right: PPC slopes downwards from left to right. It is because in a situation of fuller utilisation of the given resources, production of both the goods cannot be increased simultaneously. More of commodity A can be produced only with less production of commodity B.
2. Concave to the point of origin: It is because to produce each additional unit of commodity A, more and more units of commodity B will have to be sacrificed. Opportunity cost of producing every additional unit of commodity A tends to increase in terms of the loss of production of commodity B. Production will act upon the law of increasing marginal opportunity cost.

The three-dimensional approaches adopted by government to alleviate poverty

1. Trickle down approach: This approach assumes that the positive effects of economic growth will benefit all the sections of society whether rich or poor or very poor.

2. Poverty alleviation approach: In this approach income earning assets and employment generation opportunities were created.

3. Providing basic amenities: This approach aimed at providing basic amenities to the poor people so as to improve their health, productivity and income earning opportunities for alleviating poverty.

The effect of these three-dimensional approaches are -

a) Though there has been a reduction in the percentage of absolute poor in some of the states of India but still we cannot see that the basic amenities could reach every poor people.

b) The income earning assets and productive resources are not owned by the poor.

c) There was inequality of income from land due to land reforms.

d) The improper implementation of poverty alleviation programmes lead to increased corruption and improper and inefficient allocation of scarce resources.