9709 P52 - Nov 2024 - Q6 - 10 marks
9765
Teams of 15 runners took part in a charity run. Their completion times, in minutes, are shown below.
| Team | Times |
|---|---|
| Falcons | 38, 39, 42, 44, 46, 48, 50, 51, 52, 56, 58, 59, 64, 69, 76 |
| Kites | 32, 40, 40, 45, 47, 48, 52, 54, 58, 59, 59, 60, 61, 63, 65 |
(a) Draw a back-to-back stem-and-leaf diagram, with Falcons on the left. [4]
(b) Find the median and interquartile range for Falcons. [3]
Let \(x,y\) denote a Falcon and a Kite time respectively. It is given that \(\sum x=792,\ \sum x^2=43504,\ \sum y=783,\ \sum y^2=42223\).
(c) Find the mean and standard deviation of all 30 runners’ times. [3]
