Mathematics 9709 · AS & A Level · Sampling and estimation

Sampling and estimation — practice question

On a spring day, the heights of 200 daffodils are recorded, to the nearest centimetre. The frequency distribution is shown.
(i)[4]

Draw a cumulative frequency graph to show the data.

(ii)[2]

$28\%$ of these daffodils have height $h$ cm or above. Estimate $h$.

(iii)[3]

The estimated mean height of these daffodils, found from the table, is given as $18.39$ cm. Calculate an estimate of the standard deviation of the heights of these daffodils.

Worked solution & mark scheme

This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: 4 or more cumulative frequencies correctly obtained from the table

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