CA Foundation P3 · Chapter 17 · Question 9 of 9
When the coefficient of correlation r = 0, the two lines of regression are:
Test yourself: pick an answer
Reveal answer & explanation
Correct answer: A) Perpendicular to each other
Explanation
When r = 0, byx = bxy = 0, so the line of y on x is y = ȳ (horizontal) and the line of x on y is x = x̄ (vertical). These are perpendicular. When r = ±1 the two lines coincide.
More Correlation and Regression MCQs
- Q2If Cov(x, y) = 18, σx = 4 and σy = 6, the coefficient of correlation is:
- Q3The two regression coefficients are byx = 0.8 and bxy = 0.45. The coefficient of correlation is:
- Q4For 6 pairs of ranks, the sum of squares of rank differences Σd² = 14. Spearman's rank correlation coefficient is (to two decimals):
- Q5The two regression lines are 3x + 2y = 26 and 6x + y = 31. The means of x and y are:
- Q6The two regression lines are 3x + 2y = 26 and 6x + y = 31. The coefficient of correlation between x and y is: