Question

The scatterplot shows the number of minutes spent reading (x) and the number of pages read (y) by each of seven students last night. Use the labeled points to create a linear model that predicts the number of pages that a typical student reads in x minutes. Which equation represents this linear model?

Answer 1

I don’t have the scatterplot image or the point coordinates. Could you either upload the picture or type the seven labeled points (x,y)? Once I have the points I can compute the best-fit linear model and give the equation.

If you want to do it yourself, here are two easy options:

1) Quick eyeball line through two clear points on the trend
- Pick two points that lie on (or very near) the trend line, call them (x1,y1) and (x2,y2).
- Slope m = (y2 − y1) / (x2 − x1).
- Find b from y1 = m x1 + b → b = y1 − m x1.
- Equation: y = m x + b.

2) Least-squares (best-fit) line from all points
- Compute mean_x = average of all x, mean_y = average of all y.
- Slope m = Σ[(xi − mean_x)(yi − mean_y)] / Σ[(xi − mean_x)^2].
- Intercept b = mean_y − m * mean_x.
- Equation: y = m x + b.

Send the point coordinates (or the image) and I’ll calculate the exact equation.