12 Paul drew a cumulative frequency graph showing information about the numbers of people in various age-groups in a certain region X. He forgot to include the scale on the cumulative frequency axis, as shown below.
\includegraphics[max width=\textwidth, alt={}, center]{166bcf11-c812-4077-91c8-916b093cbbd0-09_758_936_408_561}
- Find an estimate of the median age of the population of region X .
- Find an estimate of the proportion of people aged over 60 in region X .
Sonika drew similar cumulative graphs for another two regions, Y and Z , but she included the scales on the cumulative frequency axes, as shown below.
\includegraphics[max width=\textwidth, alt={}, center]{166bcf11-c812-4077-91c8-916b093cbbd0-10_748_935_358_116}
\includegraphics[max width=\textwidth, alt={}, center]{166bcf11-c812-4077-91c8-916b093cbbd0-10_746_940_358_1011} - Find an age group, of width 20 years, in which region Z has approximately 3 times as many people as region Y.
- State one advantage and one disadvantage of using Sonika's two diagrams to compare the populations in Regions Y and Z.
- Without calculation state, with a reason, which of regions Y or Z has the greater proportion of people aged under 40.