UGC NET COMMERCE January 2017(Paper-II) Q18
0. Which one of the following is a false statement?
- A
The signs of the regression coefficients are always the same.
- B
Correlation coefficient is the geometric mean of the two regression coefficients.
- C
The co-variance between two variables divided by the product of their standard deviations produces the value of coefficient of correlation.
- D
Coefficient of correlation is independent of origin but not of scale.
- Option : B
- Explanation : Properties of Correlation Coefficient
Property-1 : Pearsonian correlation coefficient can not exceed 1 numerically. In other words it lies between –1 and +1.
Symbolically, -1 ≤ r ≤ 1
In other words, r = ± 1 implies perfect positive correlation between the variables and r = –1 implies perfect negative correlation between the variables.
Property-2 : Correlation coefficient is independent of the change of origin and scale.
Property-3 : Two independent variables are uncorrelated but the converse in not true.
