a) For every additional hour of weekly exercise, there is a corresponding 0.2 decrease in daily hours of sleep. b) We can correctly predict that a 60 -year-old adult who exercises 6 hours per week sleeps on average 7.3 hours per day. c) For every additional hour of weekly exercise, there is a corresponding 8.5 increase in daily hours of sleep. d) Increasing amounts of weekly exercise causes a decrease in daily hours of sleep