Mathematics 9709 · AS & A Level · Representation of data

Representation of data — practice question

The paired back-to-back stem-and-leaf diagram gives the yearly salaries of 19 workers in each of the two firms, Petral and Ravon. Key: $2\,|\,31\,|\,5$ represents a Petral worker earning $\$31\,200$ and a Ravon worker earning $\$31\,500$.
(a)[3]

Find the median and the interquartile range for the salaries paid to the Petral employees.

(b)[3]

Show the data in the back-to-back stem-and-leaf diagram as a pair of box-and-whisker plots on one diagram.

(c)[1]

Comment on whether the mean or the median is the better description of the data for the employees at Petral.

Worked solution & mark scheme

This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: Median correctly identified as $32000$

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