The regression line of y on x is 3x+4y+8=0, and the regression line of x on y is 4x+3y+7=0. What is the value of the Pearson correlation coefficient?

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y = (-3/4) * x - 2 x = (-3/4) * y - 7/4 b1 = -3/4 b2 = -3/4 p = b1 (x_std / y_std) p = b2 (y_std / x_std) p * p = b1 * b2 so, p = sqrt(9/16) => p = +/- 3/4 here, both slope are negative so that, p = -3/4
Ans: -3/4