CA Foundation P3 · Chapter 17 · Question 5 of 9
The two regression lines are 3x + 2y = 26 and 6x + y = 31. The means of x and y are:
Test yourself: pick an answer
Reveal answer & explanation
Correct answer: C) x̄ = 4, ȳ = 7
Explanation
Both regression lines pass through (x̄, ȳ), so solve them together. From the second, y = 31 − 6x. Substituting: 3x + 62 − 12x = 26, so 9x = 36 and x = 4; then y = 31 − 24 = 7. Hence x̄ = 4, ȳ = 7.
More Correlation and Regression MCQs
- Q7The coefficient of correlation from 25 pairs of observations is 0.8. Taking PE = 0.6745 x (1 − r²)/√n, the probable error of r is (to four…
- Q8Given x̄ = 20, ȳ = 45 and the regression coefficient of y on x, byx = 1.2, the estimated value of y when x = 25 is:
- Q9When the coefficient of correlation r = 0, the two lines of regression are:
- Q1The coefficient of correlation r always lies between:
- Q2If Cov(x, y) = 18, σx = 4 and σy = 6, the coefficient of correlation is: