Answer to Question #139143 in Statistics and Probability for Chrissy

Question

To find the equation of a regression line, y=ax+b, you need these formulas:

a=r sy/sx b=y-ax

A Data set has an r value of 0.553. If the standard deviation of the x-coordinates is 3.996, and the standard deviation of the y-coordinates is 6.203, what is the slope of the line to three decimal places?

Answer 1

The slope (a) can be calculated as follows:

$$a=r\dfrac{s_Y}{s_X}=0.553\cdot \dfrac{6.203}{3.996}\approx0.858$$

The slope of the line is $0.858.$