| Exam Board | AQA |
|---|---|
| Module | S1 (Statistics 1) |
| Year | 2008 |
| Session | January |
| Marks | 7 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Bivariate data |
| Type | Calculate r from summary statistics |
| Difficulty | Moderate -0.8 This is a straightforward application of the correlation coefficient formula r = S_xy/√(S_xx × S_yy) with given summary statistics, requiring only calculator work and basic understanding of correlation properties (scale invariance). The conceptual parts (b-d) test standard textbook knowledge about correlation interpretation and limitations. |
| Spec | 5.08a Pearson correlation: calculate pmcc5.08b Linear coding: effect on pmcc |
| Answer | Marks | Guidance |
|---|---|---|
| 2 | 99 | 95 |
I appreciate you sharing this, but the content you've provided appears to be incomplete or unclear:
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Question 2:
2 | 99 | 95
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This looks like it might be:
- A question number with some numerical data (possibly marks or codes)
- Part of a table that wasn't fully extracted
- Incomplete mark scheme content
Could you please provide the full mark scheme content for Question 2? I need the actual marking points, criteria, and annotations (M1, A1, B1, etc.) to clean it up properly.
Once you share the complete text, I'll:
- Convert all unicode symbols to LaTeX notation
- Format with one marking point per line
- Preserve all marking annotations and guidance notes
- Present it cleanly without commentary2 The head and body length, $x$ millimetres, and tail length, $y$ millimetres, of each of a sample of 20 adult dormice were measured. The following statistics are derived from the results.
$$S _ { x x } = 1280.55 \quad S _ { y y } = 281.8 \quad S _ { x y } = 416.3$$
\begin{enumerate}[label=(\alph*)]
\item Calculate the value of the product moment correlation coefficient between $x$ and $y$.
\item Interpret your value in the context of this question.
\item Write down the value of the product moment correlation coefficient if the measurements had been recorded in centimetres.
\item Give a reason why it is not generally advisable to calculate the value of the product moment correlation coefficient without first viewing a scatter diagram of the data. Illustrate your answer with a sketch.
\end{enumerate}
\hfill \mbox{\textit{AQA S1 2008 Q2 [7]}}