9 Mr. Travis tracks his students' test scores and the number of hours they studied. He found that his students score an average of 27 marks when they do not study and an average of 65 marks when they study for 3 hours. The test is out of 100 marks. a. Use a logistic model to write a function of average test scores on the number of hours studied. b. Use the model to estimate how long the students need to study to get an average of 80 marks. c. Use the model to estimate the average rate of change of test marks over the first 5 hours of studying