120 runners took part in a charity fun run. Their finishing times, in minutes, are summarised by a box plot with minimum 3, lower quartile 6, median 7, upper quartile 9 and maximum 18. The value 18 is shown as a high outlier on the box plot.
∑x=900∑x2=7230 \sum x = 900 \quad \sum x^2 = 7230 ∑x=900∑x2=7230Write down the range of the times.
Write down the interquartile range of the times.
Calculate the mean and the standard deviation of the times.
State, giving a reason, whether you would recommend using the mean and standard deviation or the median and interquartile range to describe these data.
28 exam-style questions on Edexcel AS Level Maths Representations of Data, covering 3.1 Outliers, 3.2 Box Plots, 3.3 Cumulative Frequency, 3.4 Histograms, and 3.5 Comparing Data. Each one has a worked solution and a mark scheme showing where the marks go.