Runners in a 5k race were surveyed about their finishing times (f) and the number of previous races they had run (n). there was a negative linear relationship between f and n that is best modeled by the equation f=−1.2n+38.1 .

a the model predicts that the finishing time for a runner in a 5k race is about 38.1 minutes. b the model predicts that the finishing time for a runner who has run 1.2 previous 5k races is about 38.1 minutes. c the model predicts that for each additional race a runner has run, the finishing time decreases by about 1.2 minutes. d the model predicts that the finishing time for a runner in a 5k race is about 38.1 minutes.