Mathematics 9709 · AS & A Level · Sampling and estimation

Sampling and estimation — practice question

The annual amounts of money spent on clothes, rounded to the nearest $\$10$, for 27 people are listed below: $10, 40, 60, 80, 100, 130, 140, 140, 140, 150, 150, 150, 160, 160, 160, 160, 170, 180, 180, 200, 210, 250, 270, 280, 310, 450, 570$.
(i)[3]

Draw a stem-and-leaf diagram for the data.

(ii)[3]

Find the median and the interquartile range for the data.

(iii)[3]

An ‘outlier’ is any data value that lies more than $1.5$ times the interquartile range above the upper quartile, or more than $1.5$ times the interquartile range below the lower quartile. State the outliers.

Worked solution & mark scheme

This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: Stem-and-leaf layout correct, with stems condensed where needed

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