Amir is planning a statistical investigation into how long Year 11 students spend on homework each week. He plans to collect data from a sample of students and process it using a stem-and-leaf diagram before interpreting the results.
(a)Give one reason why a stem-and-leaf diagram is a useful way to process this raw data, compared with leaving it as an unsorted list.(1)
(b)Amir collects these times, in hours, from 15 students:
3, 9, 12, 6, 17, 4, 10, 8, 19, 14, 4, 11, 9, 12, 5
Construct an ordered stem-and-leaf diagram for this data. Include a key.(3)
(c)Find the median time spent on homework.(2)
(d)Comment on what the shape of the diagram suggests about the distribution of homework times, and state whether the mean would be higher or lower than the median.(2)
(Total for Question 8 is 8 marks)