(a)[4]
Draw a histogram that displays this information.
(b)[3]
Using the data, the estimate of the mean time taken by these $250$ employees is $43.2$ minutes. Calculate an estimate for the standard deviation of these times.
Mathematics 9709 · AS & A Level · Representation of data
Representation of data — practice question
The table shows the times, in minutes, that $250$ employees at a particular company took to finish a word processing task:
Time taken ($t$ minutes): $0 \leq t < 20$, $20 \leq t < 40$, $40 \leq t < 50$, $50 \leq t < 60$, $60 \leq t < 100$.
Frequencies: $32, 46, 96, 52, 24$.