Question 6.49

14. Exercise 4 (page 278) gives data on concentration (in parts per million) over time. A regression line for predicting for a given year is

281

  1. What is the slope of this line? What does the slope say about how is changing over time?
  2. What does the model predict the concentration for 2006 to be? In fact, the observed value that year was 381.85. How accurate is your prediction?