Write down the modal grade.

Find the mean grade.

Write down the standard deviation.

Find the interquartile range.

\(6\)     (A1)     (C1)

[1 mark]

\(\frac{{5 + 3 + 6 +  \ldots  + 4}}{{13}}\)     (M1)

Note: Award (M1)for correctly substituted mean formula, division by 13 must be seen.

\( = 4.85\left( {\frac{{63}}{{13}}} \right)\)    \({\text{(4}}{\text{.84615}} \ldots {\text{)}}\)     (A1)     (C2)

[2 marks]

\({\text{1}}{\text{.46}}\)     \({\text{(1}}{\text{.4595}} \ldots )\)     (A1)     (C1)

[1 mark]

\(6 - 3.5\)     (M1)

\( = 2.5\)     (A1)     (C2)

Note: Award (M1) for their quartiles seen or a correct ordered list. Accept a correct ordered list from any previous part of the question.

[2 marks]

Whilst many knew what the mode was, there was some confusion by weaker candidates who interpreted the required value as the maximum value in the list, namely \(7\). Many candidates gave the correct value of the mean in part (b) but a surprising number seemed to have selected the incorrect value from their calculator display for the standard deviation. In mathematical studies, the smaller value of the standard deviation, \({\sigma _x}\), should be given. In part (d), ordered lists were often seen but it proved problematic for a significant number of candidates to find \({Q_1}\)and \({Q_3}\). Common mistakes such as \({Q_3} = \frac{{6 + 6}}{2} = 6.5\) and \({Q_1} = 3\) were seen on many scripts.

Whilst many knew what the mode was, there was some confusion by weaker candidates who interpreted the required value as the maximum value in the list, namely \(7\). Many candidates gave the correct value of the mean in part (b) but a surprising number seemed to have selected the incorrect value from their calculator display for the standard deviation. In mathematical studies, the smaller value of the standard deviation, \({\sigma _x}\), should be given. In part (d), ordered lists were often seen but it proved problematic for a significant number of candidates to find \({Q_1}\)and \({Q_3}\). Common mistakes such as \({Q_3} = \frac{{6 + 6}}{2} = 6.5\) and \({Q_1} = 3\) were seen on many scripts.

Whilst many knew what the mode was, there was some confusion by weaker candidates who interpreted the required value as the maximum value in the list, namely \(7\). Many candidates gave the correct value of the mean in part (b) but a surprising number seemed to have selected the incorrect value from their calculator display for the standard deviation. In mathematical studies, the smaller value of the standard deviation, \({\sigma _x}\), should be given. In part (d), ordered lists were often seen but it proved problematic for a significant number of candidates to find \({Q_1}\)and \({Q_3}\). Common mistakes such as \({Q_3} = \frac{{6 + 6}}{2} = 6.5\) and \({Q_1} = 3\) were seen on many scripts.

Whilst many knew what the mode was, there was some confusion by weaker candidates who interpreted the required value as the maximum value in the list, namely \(7\). Many candidates gave the correct value of the mean in part (b) but a surprising number seemed to have selected the incorrect value from their calculator display for the standard deviation. In mathematical studies, the smaller value of the standard deviation, \({\sigma _x}\), should be given. In part (d), ordered lists were often seen but it proved problematic for a significant number of candidates to find \({Q_1}\)and \({Q_3}\). Common mistakes such as \({Q_3} = \frac{{6 + 6}}{2} = 6.5\) and \({Q_1} = 3\) were seen on many scripts.