The frequency table below shows the number of hours spent learning a new song. # of hours Midpoint O up to 3 3 up to 6 Frequency 3 6 up to 9 9 up to 12 6 15 10 12 up to 15 7 15 up to 18 2 a) Show how we determined six is the appropriate number of classes for this sample. (1 mark) b) Draw a frequency polygon based on your table above. Title the axes. (2 marks) c) What is the mean number of hours? (1 mark)