In a study of how much time students spend on social media, usage of a random sample of 15 students was examined for a particular day. The total time of usage, x x\,x minutes, for the 15 students were:
5, 10, 15, 25, 30, 35, 40, 45, 50, 55, 60, 70, 80, 85, 90
Find the median and quartiles for these data.
Calculate Q3−Q1Q_3-Q_1Q3−Q1.
A value that is greater than Q3+1.5×(Q3−Q1)Q_3 + 1.5 \times (Q_3 - Q_1)Q3+1.5×(Q3−Q1) or smaller than Q1−1.5×(Q3−Q1)Q_1 - 1.5 \times (Q_3 - Q_1)Q1−1.5×(Q3−Q1) is defined as an outlier. Show that there are no outliers.
Draw a box plot for these data.

160 exam-style questions on Edexcel A 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.