A data set has a correlation coefficient of r = −0.9, with the means of marginal distributions of = 1 and = 2. It is known that one of the following four equations corresponds to the regression of y on x:
Select the correct line.
y = −x + 2 3x − y = 1 2x + y = y = x + 1
Since the linear correlation coefficient is negative, the slope of the line will also be negative, thus ruling out the 2nd and 4th options.
A point on the line is (, ), that is to say, (1, 2).
2 ≠ −1 + 2
2 · 1 + 2 = 4
The correct line is: 2x + y = 4.