| Exam Board | Edexcel |
|---|---|
| Module | S1 (Statistics 1) |
| Year | 2009 |
| Session | June |
| Marks | 6 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Bivariate data |
| Type | Calculate summary statistics (Sxx, Syy, Sxy) |
| Difficulty | Easy -1.2 This is a straightforward calculation question requiring direct substitution into standard formulas for Sxx, Sxy, and the correlation coefficient. All summations are provided, requiring only arithmetic and formula recall with no problem-solving or interpretation beyond a standard statement about correlation strength. |
| Spec | 5.08a Pearson correlation: calculate pmcc5.08b Linear coding: effect on pmcc |
\begin{enumerate}
\item The volume of a sample of gas is kept constant. The gas is heated and the pressure, $p$, is measured at 10 different temperatures, $t$. The results are summarised below.\\
$\sum p = 445 \quad \sum p ^ { 2 } = 38125 \quad \sum t = 240 \quad \sum t ^ { 2 } = 27520 \quad \sum p t = 26830$\\
(a) Find $\mathrm { S } _ { p p }$ and $\mathrm { S } _ { p t }$.
\end{enumerate}
Given that $\mathrm { S } _ { t t } = 21760$,\\
(b) calculate the product moment correlation coefficient.\\
(c) Give an interpretation of your answer to part (b).\\
\hfill \mbox{\textit{Edexcel S1 2009 Q1 [6]}}