Question

Dan drew the line of best fit on the scatter plot shown below: A graph is shown with scale along x axis from 0 to 10 at increments of 1 and scale along y axis from 0 to 15 at increments of 1 and scale along y axis from 0 to 15 at increments of 1. The ordered pairs 0, 4 and 1, 4 and 2, 5 and 3, 6 and 4, 7 and 5, 9 and 6, 10 and 7, 11 and 8, 13 and 9, 14 and 10, 15 are shown on the graph. A straight line joins the ordered pairs 0, 3 and 10, 15. What is the equation of this line of best fit in slope-intercept form?

Answer 1

     0, 3
-   10, 15
= -10, -12
therefore, the slope is 6/5, and the intercept (c) is as supplied, 3.
the equation, y=mx+c or y = a + bx, can be applied here where m or b = 6/5, and a or c = 3.

therefore the equation is y=6/5x+3.

To test this, you can put in y = 10(6/5)+3, which spits out y = 15. This way we know it *should* work.