Given the line of best fit for a set of data points with the equation y=5x-2.5, what is the residual for the point (3,6)?

Explanation:

For the x value x = 3, the observed y value is y = 6 which is from the point (3,6).

The predicted y value is found by plugging x = 3 into the line of best fit equation

y = 5x-2.5

y = 5(3)-2.5

y = 12.5

The residual is the difference between the two y values

e = residual

e = (observed y value) - (predicted y value)

e = 6 - 12.5

e = -6.5

The negative residual tells us the observed y value is smaller than the predicted y value for this given x value.