Mathematics 9709 · AS & A Level · Representation of data

Representation of data — practice question

Last Saturday, 15 runners in each team joined a charity run. The table shows the finishing times, in minutes, for the Falcons runners and the Kites runners as they completed the course.
(a)[4]

Draw a back-to-back stem-and-leaf diagram to show this data, with the Falcons on the left-hand side.

(b)[3]

Find the median and the interquartile range for the Falcons’ times.

(c)[3]

Let $x$ and $y$ represent the times, in minutes, of a runner from the Falcons and a runner from the Kites respectively. It is given that $\sum x = 792$, $\sum x^2 = 43\,504$, $\sum y = 783$, $\sum y^2 = 42\,223$. Determine the mean and standard deviation of the times taken by all 30 runners from the two teams.

Worked solution & mark scheme

This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: Stem values drawn correctly

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