5. A trainee manager wondered whether the length of time his trainees revised for an exam had any effect on their results. A random sample of trainees was asked to estimate how long they spent revising to the n earest hour. After the exam he investigated the relationship between the two variables. Trainee: ABCDEFGHIJ Revision time: 491014471222117 Exam mark (\%): 31586573374460912184 Use Excel to answer the following questions. Enter the data into two columns. (a) Plot a scatter diagram (decide which is the dependent variable first!) (b) Calculate the correlation coefficient (c) Find the regression model (d) Predict the exam mark for a trainee who revises for 15 hours (e) Predict the exam mark for a trainee who revises for 35 hours (f) Comment on your answer to (e)