1 Sophie was sick of her daily commute. ‘Why’, she thought, ‘should I have to spend so much time in the morning stuck in traffic listening to some babbling halfwit on the radio? We can work flexi-time, after all. Perhaps I should leave the apartment at some other time?’ So resolved, Sophie deliberately varied her time of departure from her usual 8.30 am. Also, being an organised soul, she recorded her time of departure and her journey time each day. Her records are shown in Table¦15.1.

(a) Draw a scatter diagram that will help Sophie decide on the best time to leave her apartment.

(b) How much time per (5-day) week should she expect to be saved from having to listen to a babbling halfwit?