8. (12 points) The total number of animal and plant species in a certain country that are listed as endan- gered or threatened are shown in the table for various years. Let n be the number of species that are listed as endangered or threatened at f years since 1980. Page 2 Number of Year Species Listed 1985 383 1990 595 1995 962 2000 1243 2005 1264 2011 1968 (a) (4pts) What is the explanatory variable and the response variable? (b) (4pts) Does this show a linear association? If so, what type is it? (c) (2pts) What is the possible value of r? (r = 0, 1, 0.8, -1, -0.9) (d) (2pts) Use the linear model on the scatterplot to predict the number of species listed as endangered or threatened for t= 22