| Exam Board | Edexcel |
|---|---|
| Module | S1 (Statistics 1) |
| Marks | 6 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Bivariate data |
| Type | Assess appropriateness of correlation analysis |
| Difficulty | Moderate -0.8 This is a straightforward S1 question testing basic understanding of statistical models and distributions. Part (a) requires simple recall/explanation, part (b) expects 'normal distribution' as a standard answer, parts (c-d) test basic reasoning about distribution properties. The correlation/time series component is descriptive rather than computational. Easier than average A-level as it's mostly conceptual recall with no calculations. |
| Spec | 2.01a Population and sample: terminology |
| Year | 1993 | 1994 | 1995 | 1996 | 1997 | 1998 | 1999 | 2000 | ||
| 21.9 | 24.1 | 20.7 | 23.0 | 24.2 | 22.1 | 22.6 | 23.9 |
| Answer | Marks | Guidance |
|---|---|---|
| (a) e.g. using a distribution or other simplified way of representing a real situation that allows predictions to be made about it | B2 | |
| (b) Normal | B1 | |
| (c) e.g. most values close to mean; roughly symmetrical | B2 | |
| (d) e.g. male and female mean weights may differ giving bimodal distribution | B1 | (6 marks total) |
(a) e.g. using a distribution or other simplified way of representing a real situation that allows predictions to be made about it | B2 |
(b) Normal | B1 |
(c) e.g. most values close to mean; roughly symmetrical | B2 |
(d) e.g. male and female mean weights may differ giving bimodal distribution | B1 | (6 marks total)\begin{enumerate}
\item (a) Explain briefly what you understand by a statistical model.\\
(2 marks)\\
A zoologist is analysing data on the weights of adult female otters.\\
(b) Name a distribution that you think might be suitable for modelling such data.\\
(1 mark)\\
(c) Describe two features that you would expect to find in the distribution of the weights of adult female otters and that led to your choice in part (b).\\
(2 marks)\\
(d) Why might your choice in part (b) not be suitable for modelling the weights of all adult otters?\\
(1 mark)
\item For a geography project a student studied weather records kept by her school since 1993. To see if there was any evidence of global warming she worked out the mean temperature in degrees Celsius at noon for the month of June in each year.
\end{enumerate}
Her results are shown in the table below.
\begin{center}
\begin{tabular}{ | c | c | c | c | c | c | c | c | c | }
\hline
Year & 1993 & 1994 & 1995 & 1996 & 1997 & 1998 & 1999 & 2000 \\
\hline
\begin{tabular}{ c }
Mean temperature \\
$\left( { } ^ { \circ } \mathrm { C } \right)$ \\
\end{tabular} & 21.9 & 24.1 & 20.7 & 23.0 & 24.2 & 22.1 & 22.6 & 23.9 \\
\hline
\end{tabular}
\end{center}
\hfill \mbox{\textit{Edexcel S1 Q1 [6]}}