manufacture) and price. Identify the observational units. Produce a scatterplot of price vs. age. Describe the association revealed in the graph. Determine the least squares line for predicting price from age and produce a scatterplot with the least squares line superimposed. Report and interpret the value of the slope coefficient. What percentage of the variability in car prices is explained by knowing the car's age? Chapter 10.3 Exercise Question 20 Textbook prices Two Cal Poly freshmen gathered data on a random sample of textbooks from the campus