The less–than and more–than cumulative frequency curves are both used for studying grouped data.
Prepare clear and concise answers to the following:
(i) Explain the difference between a less–than cumulative frequency distribution and a more–than cumulative frequency distribution.
(ii) Describe, step by step, how the two corresponding curves are plotted on graph paper, mentioning the axes chosen and the points to be marked.
(iii) A teacher claims that the median of a grouped data set can be obtained graphically using only the less–than cumulative frequency curve. State how this can be done and justify why the method works.