There are additional parts to the question: b) A normal probability plot of the residuals indicates that the residuals are approximately normally distributed. Test whether a linear relation exists between year and population. c) Draw a scatter diagram, treating year as your explanatory variable. d) Plot the residuals against the explanatory variable, year. e) Does a linear model seem appropriate based on the scatter diagram and residual plot? f) What is the moral? Is the linear model appropriate? Compare with part b)