Mathematics 9709 · AS & A Level · Sampling and estimation
Sampling and estimation — practice question
The cumulative frequency graph gives annual salaries, in thousands of euros, for a random sample of 500 adults with jobs in France. It was drawn from grouped data. You may assume that the lowest salary is $5000$ euros and the highest salary is $80\,000$ euros.
(i)[4]
On graph paper, draw a box-and-whisker plot for these salaries.
(ii)[1]
Make a comment about the salaries of the people in this sample.
(iii(a))[3]
An ‘outlier’ is any data value that is 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. How large must a salary be to count as an outlier?
(iii(b))[1]
Show that none of the salaries is small enough to count as an outlier.
Worked solution & mark scheme
This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: “$LQ = 15$, median $= 18$, $UQ = 26$” …