The curve which shows the combinations of two goods and services that can be produced with fuller utilisation of a given amount of resources in the most efficient way and with a given production technology is called Production Possibility Curve. It is also known as Production Possibility Frontier (or PPF) and Transformation Curve. The following are the properties of a PPC.

i. Concave to Origin: PPC curve is concave to the origin. This is because of the increasing opportunity cost i.e. in accordance with the law of increasing opportunity cost.

ii. Increasing Marginal Rate of Transformation: The slope of PPC (MRT) shows, for the production of every additional unit of one good, more and more units of other good has to be sacrificed. In other words, as we move down along the PPC, the slope of PPC (or MRT) increases.

iii. Downward Sloping: PPC curve is downward sloping as more production of one good is associated with the decline in production of the other good.

iv. Optimum utilisation of resources: The points that lie on the Production Possibility Frontier are associated with full employment of resources and efficient utilisation of the available technology.
 

The universe (Latin: universus) is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy. At the largest scale, galaxies are distributed uniformly and the same in all directions, meaning that the universe has neither an edge nor a center.

Only a point that lies on the budget line can be the equilibrium point because of the fact that only the combination of goods as represented by these points is affordable by the consumer given his income. On the other hand, the points that lie above the budget line are not affordable by the consumer, thereby, cannot be the equilibrium. In contrast to this, consumption bundles that lie below the budget line leave the consumer with some unspent income. This suggests that the consumer can have more of at least one of the goods and no less of the other. Thus, only a point on the budget line can be the equilibrium point for a consumer. 

 Published sources are the sources used for collection of secondary data. These sources are in the form of reports and newspapers which are provided by government publications, private publications and foreign publications. For instance, Reserve Bank of India Bulletin, Indian trade journals, reports on currency and finance and reports by private companies, the Address of a person taken from the Telephone Directory or Phone number of a company taken from ‘Just Dial’ are all examples of published sources of data. 

1. Aggregate of Facts: Single or isolated figures are not considered to be statistics because such figures are unrelated and cannot be compared. A single figure of the boy of 26 years would not constitute statistics. It is just a numerical statement the fact. Statistical data are concrete numbers which represent objects
2. Systematically Arranged: A proper plan should be prepared before collecting the statistical data. Data collected in a haphazard manner would lead to false conclusions. Therefore, data should be collected in a systematic manner.
3. Statistics are Estimated or Enumerated: According to the feature of statistics, data can be enumerated or estimated. If the numerical statements are precise accurate, then they can be enumerated. Contrary to this, if the field of investigation large and beyond comprehension, then the estimation procedure can be adopted.
4. Statistics are numerically expressed: All statistics are expressed numerical figures i.e. expressed in numbers and related to quantitative information only. Qualitative characteristics do not come under statistics unless they are assigned cert; ranks as a quantitative measure of assessment.
5. Statistical Data Collected for a Pre Determined Purpose: Collected should be, for a pre determined purpose. The figures are collected with some goal objective in mind. Without any objective collected data will be useless. Thus, the purpose of collecting data must be decided in advance.
6. Placed in Relation to each other: Numerical information's must be mud related and comparable. In the absence of such a quality the statistics would se, purpose. For example, statistics related to number of children born, exports country, coal production etc. have no relevance for statistical 

The differences between a discrete and continuous variables are :

Discrete Variable: A discrete variable can take only certain values.Its value changes only by finite ‘jumps’. It jumps from one values to another but does not take any intermediate value between them.
For example, in number of students in class Xlth could be 1,2,4,10,11,15,20, etc.

Continuous Variable : A continuous variable is the one which can take any value in a specified interval.
For exomp/e, temperature recorded of patients a hospital, wages of all workers in a factory, etc.

Data are raw facts and figures (ie) Unorganised information . 

The two main sources of data are Primary and Secondary sources 

Questionnaire: A form containing questions to which a subject or subjects respond. The information gained from the questionnaire is often subjected to statistical analysis. Questionnaires can be used to examine the general characteristics of a population, to compare attitudes of different groups and to test theories. Questionnaires appear simple but they are very difficult to compile in a manner which establishes reliability and validity. For example, a question worded in one way, may elicit a different response from the same question worded slightly differently.
Following are the characteristics of a good questionnaire:
(i) Questions must be worded simply and clearly, not ambiguous or vague. It must be objective.
(ii) Attractive in appearance (questions spaced out and neatly arranged).
(iii) Write a descriptive title for the questionnaire.
(iv) Write an introduction to the questionnaire
(v) Order questions in a logical sequence.
(vi) Keep questionnaire uncluttered and easy to complete.
(vii) Design for easy tabulation.
(viii) Design to achieve objectives.
(ix) Define each and every term.
(x) Avoid double negatives (I have no money).
(xi) Avoid double barreled questions (this AND that).
(xii) Frame questions for all respondents.

In Indirect Oral Investigation, data is collected through indirect sources. Persons who are likely to have information about the problems, are interrogated and on the basis of their answers, factual data have to be compiled. Most of the commissions of enquiry appointed by government collect primary data by this method. The accuracy of the method depends largely upon the type of persons interviewed and hence these persons have to be selected very carefully.

• In a simple random sample, each sample of size n has equal probability to be included. The clusters to be added are randomly selected and then the members of each selected cluster are added.
• Only possible models, including each kth item from a random starting point, are possible.
• A simple random sample consists of random samples from each level.

• Systematic sampling  each sample of size n is added equally. Only possible models, including each item from a random starting point, are possible.
• The clusters to be added are randomly selected and then the members of each selected cluster are added.
• In a systematic sampling , random samples from each level are included.

• It is the process of arranging data into homogeneous (similar) groups according to their common characteristics.
• Raw data cannot be easily understood, and it is not fit for further analysis and interpretation. This arrangement of data helps users in comparison and analysis.
• For example, the Population of town can be grouped according to ***, age, marital status etc.

The law of diminishing marginal productivity is also known as the law of diminishing marginal returns. Marginal productivity or marginal product refers to the extra output, return, or profit yielded per unit by advantages from production inputs. Inputs can include things like labor and raw materials. Marginal physical product, usually abbreviated MPP, is found by dividing the change in total physical product by the change in the variable input.

A mixed economy is variously defined as an economic system blending elements of a market economy with elements of a planned economy, free markets with state interventionism, or private enterprise with public enterprise. A mixed economic system is a system that combines aspects of both capitalism and socialism. A mixed economic system protects private property and allows a level of economic freedom in the use of capital, but also allows for governments to interfere in economic activities in order to achieve social aims.

Following are the qualities of a good questionnaire.

1. The length of questionnaire should be proper one.
2. The language used should be easy and simple.
3. The term used are explained properly.
4. The questions should be arranged in a proper way.
5. The questions should be in logical manner.
6. The questions should be in analytical form.
7. Complex questions should be broken into filter questions.
8. The questions should be described precisely and correctly.
9. The questionnaire should be constructed for a specific period of time.
10. The questions should be moving around the theme of the investigator.

Difference between Partnership and Joint Hindu family

1. Formation - The basis of Partnership firm is a contract between persons whereas a Hindu undivided family is created by status i.e., a person becomes its member by virtue of his being born in the particular family.

2. Addition of a new partner or member - When a new partner has to be introduced into a partnership firm, consent of all the partners is needed for the same whereas no such consent is needed for the addition of a member into the joint Hindu family. A person becomes the member of the family on being born in that family.

3. Mutual agency - There is mutual agency between the partners of a particular firm, and the act done by any of the partners binds the firm whereas there is no such mutual agency between the members of a joint Hindu family. The Karta of the joint Hindu  family  has all  the powers  to act  on the  behalf  of the family  and he is the only  person  who can  represent  the family.

4. Liability - The liability  of a partner  is not  only  joint  liability or limited to his  share  in the partnership  business, the liability  is several  liability   also. Such liability is unlimited and even a partner’s personal property can be attached for the partnership debts. On the other hand, the liability of the coparceners, on the other hand, is limited only to the extent of their shares in the family business.

5. Minor - A minor cannot become a partner in a firm, he can be admitted only for the benefits whereas a person becomes a coparcener right from his birth.