The masses of 30 students of a school team are given in the grouped table below. The arithmetic mean of the distribution has already been calculated to be 63.4 kg.
Mass (kg): 50–55 55–60 60–65 65–70 70–75
Frequency: 2 5 12 8 3
(i) Calculate the median mass.
(ii) Calculate the mode of the distribution.
(iii) Which of the three measures—mean, median or mode—would you report as the ‘average’ mass for this group? Give one reason for your choice.