Write down the median length of these leaves.

Write down the number of leaves with a length less than or equal to 8 cm.

Use the graph to find the value of \(k\).

Before measuring, the researcher estimated \(k\) to be approximately 9.5 cm. Find the percentage error in her estimate.

9 (cm)     (A1)     (C1)

[1 mark]

40 (leaves)     (A1)     (C1)

[1 mark]

\((200 \times 0.90 = ){\text{ }}180\) or equivalent     (M1)

Note:     Award (M1) for a horizontal line drawn through the cumulative frequency value of 180 and meeting the curve (or the corresponding vertical line from 10.5 cm).

\((k = ){\text{ }}10.5{\text{ (cm)}}\)     (A1)     (C2)

Note:     Accept an error of ±0.1.

[2 marks]

\(\left| {\frac{{9.5 - 10.5}}{{10.5}}} \right| \times 100\% \)     (M1)

Notes:     Award (M1) for their correct substitution into the percentage error formula.

\({\text{9.52 (% ) }}\left( {{\text{9.52380}} \ldots {\text{ (% )}}} \right)\)     (A1)(ft)     (C2)

Notes:     Follow through from their answer to part (c)(i).

Award (A1)(A0) for an answer of \( - 9.52\) with or without working.

[2 marks]