Class 11 Economics Sandeep Garg Solutions Chapter 8 – Measures of Correlation
FAQs on Sandeep Garg Economics Class 11 Solutions for Chapter 8
1. What is Correlation? What are the different types of Correlation?
Ans: A correlation is a statistical method to examine the relationship between two variables, e.g. a change in price leads to a change in quantity demanded. Correlation determines the direction and intensity of the relationship between variables. However, correlation does not prove causation. There are two types of correlation: positive and negative. Positive correlations occur when variables move in the same direction. For instance, ice cream sales and temperatures move in the same direction. When the variables move in the opposite direction, it is said that the correlation is negative. You can get a detailed explanation on correlation and types in the solutions and sample pdf available at Vedantu.
2. Rank ten artisans of a facility based on their capabilities as judged by two separate people: What is their coefficient of rank correlation?
Artisans Name | P | Q | R | S | T | U | V | W | X | Y |
The position given by Judge P | 2 | 9 | 5 | 5 | 2 | 2 | 4 | 7 | 8 | 10 |
The position given by Judge R | 3 | 8 | 5 | 7 | 2 | 3 | 2 | 5 | 10 | 9 |
Ans:
Artisans Name | The position given by Judge RP | The position given by Judge RR | D= RP−RR | D2 |
P Q R S T U V W X Y | 2 9 5 5 2 2 4 7 8 10 | 3 8 5 7 2 3 2 5 10 9 | -1 1 0 -2 0 -1 2 2 -2 1 | 1 1 0 4 0 1 4 4 4 1 |
ΣD2=20 |
N= 10
\[p=1-\frac{6\sum d_{i}^{^{2}}}{n\left ( n^{2} -1\right )}\]
Or, ρ = 1- 6X20
----------------
1000-10
ρ= 1 – 0.121
ρ = 0.88
Hence, the coefficient of rank correlation is 0.88
3. Is it possible to measure any type of relationship using a simple correlation coefficient?
Ans: No, the simple correlations cannot measure all types of relationships. Only the direction and magnitude of the linear relationship between the two variables can be determined by the simple correlation coefficient. Non-linear relationships like quadratic, trigonometric, cubic between variables cannot be interpreted by the model. Correlation coefficients that appear to return zero either mean there is no correlation or the relation are nonlinear and cannot be measured. A simple correlation coefficient X = Y2 may illustrate that X and Y are not correlated, and, therefore, both variables should be considered independent, but this may be incorrect.
4. In what situations is rank correlation more precise than a simple correlation coefficient?
Ans: Following situations require rank correlation over simple correlation coefficient
It is not possible to precisely measure the height and weight of people when a measuring rod or weighing scale is not available, for example, in an isolated village where measuring rods are not available, but they can be ranked in terms of height and weight based on their measurements.
Quantifying qualitative data can be challenging because it is difficult to quantify qualities such as fairness, honesty, etc. In lieu of quantifying qualitative data, the ranking may be more appropriate.
Data with extreme values Sometimes the correlation coefficient between two variables with extreme values may differ substantially from the correlation coefficient between the two variables without extreme values. In such situations, rank correlation represents a superior way to compare variables.
5. What is the importance of making notes for each topic if you intend to score well?
Ans: In reading topics from the worksheet or other topics, making notes is the most important part. By doing this, it will be simple for you to comprehend the notes quickly rather than having to rely upon the chapter reading. Revision notes keep you on top of what you have learned. These notes will come in handy when it is time for revision before the class 11th exams. Make sure you use them during your tests. Students will benefit from the revision notes for class 11 exams, as they will not only save time during the examination but will also be able to recall what they have read or studied during the examination. The notes will also enable the students to remember every little detail regarding the most difficult subject and the easiest subject.
