Mathematics 4024 · O Level · Cumulative frequency diagrams
Cumulative frequency diagrams — practice question
The table lists the time, $t$ seconds, needed by each student to finish a puzzle. A different group, made up of adults, also completed the puzzle. Their times are represented on a cumulative frequency diagram.
(a(i))[1]
Find how many students took 2 minutes 20 seconds or less to complete the puzzle.
(a(ii))[3]
Calculate an estimate of the mean time taken, in seconds, to complete the puzzle.
(b(i))[2]
Use the cumulative frequency diagram to complete the frequency table.
(b(ii))[1]
Use the cumulative frequency diagram to estimate the median.
(b(iii))[3]
55% of the adults took between 125 seconds and $k$ seconds to complete the puzzle. Use the cumulative frequency diagram to determine $k$.
Worked solution & mark scheme
This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: “39 students” …