Question

How are the slope and intercept of a simple lonear regression line calculator? What do they tell us about the relationship between the two variables?

Answer 1

For a simple linear regression, the equation is:

y = A + Bx

Where B is the slope coefficient

And A is the intercept

We calculate them as follows:

B= Sxy/Sxx and A= mean of y - B*mean of x

Now, Sxy =

Sxx=

Mean of y=

Mean if x=

So we can put the data points in the above equations and find the slope and intercept coefficients.

Now, Slope tells us the change in y for a unit change in x. If it's positive it indicates a positive change in y, ie positive relationship between x and y. If it's negative it indicates a negative relationship between x and y.

Intercept tells us the point of y where x=0.