Question

Data was collected on the amount of time that a random sample of 8 students spent studying for a test and the grades they earned on the test. A scatter plot and line of fit were created for the data.

Determine the equation of the line of fit.

y = 5x + 60
y = 5x + 70
y = 10x + 60
y = 10x + 70

Answer 1

In slope-intercept form (y = mx + b), m represents the slope (rise/run) and b represents the y-intercept.

Let's look at the graph and pick two points, (2, 70) and (4, 80) and use slope formula, y2 - y1 / x2 - x1
80 - 70 / 4 - 2
10 / 2
5
The slope of this line is 5.

To find the y-intercept, we look where the line crosses through the y-axis or the vertical line.
The y-intercept is (0, 60) or 60

If we plug these numbers into slope-intercept form, we get y = 5x + 60

Your answer is y = 5x + 60