Jennie is a piano teacher who teaches nine pupils.

She records how many hours per week they practice the piano along with their most recent practical exam score.

\begin{tabular}{|l|c|c|}
  \hline
  \textbf{Student} & \textbf{Practice (hours per week)} & \textbf{Practical exam score (out of 100)} \\
  \hline
  Donovan    & 50   & 64 \\
  \hline
  Vazquez    & 6    & 71 \\
  \hline
  Higgins    & 3    & 55 \\
  \hline
  Begum      & 2.5  & 47 \\
  \hline
  Collins    & 1    & 80 \\
  \hline
  Coldbridge & 4    & 61 \\
  \hline
  Nedbalek   & 4.5  & 65 \\
  \hline
  Carter     & 8    & 83 \\
  \hline
  White      & 11   & 92 \\
  \hline
\end{tabular}

\begin{tikzpicture}[
    x=0.18cm, 
    y=0.09cm,
    font=\sffamily,
    cross/.pic = {
        \draw[thick] (-3.5pt, -3.5pt) -- (3.5pt, 3.5pt);
        \draw[thick] (-3.5pt, 3.5pt) -- (3.5pt, -3.5pt);
    }
]

% 1. Draw Axis Lines
\draw (0,0) -- (60,0);
\draw (0,0) -- (0,100);

% 2. X-axis Ticks and Labels
\foreach \x in {0, 10, 20, 30, 40, 50, 60} {
    \draw (\x, 0) -- ++(0, -4pt) node[below] {\x};
}

% 3. Y-axis Ticks and Labels
\foreach \y in {0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100} {
    \draw (0, \y) -- ++(-4pt, 0) node[left] {\y};
}

% 4. Axis Titles
\node[anchor=north, yshift=-22pt] at (30, 0) {Practice (hours per week)};
\node[anchor=east, align=left, xshift=-35pt] at (0, 50) {Practical \\ exam score \\ (out of 100)};

% 5. Data Points
\pic at (50, 64)  {cross};
\pic at (6, 71)   {cross};
\pic at (3, 55)   {cross};
\pic at (2.5, 47) {cross};
\pic at (1, 80)   {cross};
\pic at (4, 61)   {cross};
\pic at (4.5, 65) {cross};
\pic at (8, 83)   {cross};
\pic at (11, 92)  {cross};

\end{tikzpicture}

\begin{enumerate}[label=(\alph*)]
\item Identify two possible outliers by name, giving a possible explanation for the position on the scatter diagram of each outlier. [4 marks]

\item Jennie discards the two outliers.

\begin{enumerate}[label=(\roman*)]
\item Describe the correlation shown by the scatter diagram for the remaining points. [1 mark]

\item Interpret this correlation in the context of the question. [1 mark]
\end{enumerate}
\end{enumerate}

\hfill \mbox{\textit{AQA AS Paper 2 2018 Q18 [6]}}