Question

What is the y-intercept of the least squares regression line for the following data?: (1,1) (2,5) (3, 10)

Answer 1

`-3,667`

Explanation:

Entering these points into the calculator in stat mode yields :

Gradient : 4,5
y-intercept : -3,667

Hence the least squares line of best linear approximation through all these points has equation `y=4,5x-3,667` and is a very good approximation since the coefficient of correlation, r = 0,998 is very close to 1.

Graphically :

graph{4.5x-3.667 [-22.8, 22.83, -11.4, 11.4]}