Question 2
In a study of how students use their mobile telephones, the phone usage of a random sample of 11 students was examined for a particular week. The total length of calls, y y\,y minutes, for the 11 students were:
15, 24, 32, 39, 48, 54, 58, 61, 71, 79, 145
a.[6]
Find the median and quartiles for these data and show that 145 is the only outlier, where 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.
b.[3]
Draw a box plot for these data indicating clearly the position of the outlier.
Representations of Data Questions
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.