NCERT Solutions for Class 11 Statistics Chapter 2 Collection Of Data

Ans : (i) (a) Colour 
(b) Price 
(c) Brand 
(d) Quality of cloth


(ii) (a) Everyday 
(b) 6 times a week 
(c) 4 times a week 
(d) 2 times a week


(iii) (a) The Times of India 
(b) The Hindu 
(c) Indian Express 
(d) Dainik Bhaskar


(iv) (a) Because of increase in supply for petrol 
(b) Because of abundance of petrol 
(c) Because of hike in excise duty on petrol 
(d) Because of appreciation of rupee


(v) (a) Less than Rs 30,000 
(b) RS 30,000 to RS 50,000 
(c) RS 50,000 to RS 
(d) More than Rs 1,00,000 

Ans : 1. Do you have a car in your family? 
2. Do you like economics? 
3. Have you ever been out of your country? 
4. Have you ever visited Taj Mahal? 
5. Have to contribute towards Swaach Baharat Abhiyan? 

Ans : (i) True 
Reason: There are many sources of data collection which can be categories under two heads Primary data sources and secondary data sources. Primary data sources consists of Direct personal interviews, Indirect oral investigations, Information through mailed Questionnaire or Information through questionnaire filled by enumerators. The sources of secondary data includes published sources like books, magazine, government survey reports etc. and unpublished sources like research papers, company documents, etc.


(ii) False 
Reason: Telephone survey is most suitable method of collecting data when population is illiterate. When population is literate and spread over a large area the most suitable method is mailed questionnaire method.


(iii) False 
Reason: Data collected by the investigator himself is called primary data; the data collected by some other agency and which is already available for furthers studies are called secondary data.


(iv) True 
Reason: Non-random sampling is done on the basis of judgement and convenience of the investigator hence it is not free of certain bias like personal prejudice.


(v) False 
Reason: Non-sampling errors are more serious than sampling errors and it is difficult to minimize them, ever by taking a large sample. Some of the non-sampling errors are: errors in data Acquisition, non-response errors, sampling bias, processing errors, etc. 

Ans : (i) This question is quite ambiguous and respondent might find it difficult to answer it with certainty.


(ii) This question is too long; it might discourage respondent to answer. It also gives a clue about how the respondent should answer which can influence the respondents answer, it should be avoided.


(iii) This question contains double negatives. The questions starting with "wouldn’t you" or "don’t you" should be avoided as they may create confusion and lead to biased responses.


(iv) (v) (vi) The above three questions (iv, v and vi) are correct but the order in which they have been asked is not correct. One should always ask the general questions first and then should move towards more specific ones. This helps the respondents to feel comfortable. 
The correct order to ask these questions would have been. 
i. What is the yield per hectare in your field? 
ii. Do you use fertilisers In your fields? 
iii. Do you agree with the use of chemical fertilisers? 

Ans : DIY