| Exam Board | OCR MEI |
|---|---|
| Module | S1 (Statistics 1) |
| Year | 2011 |
| Session | June |
| Marks | 5 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Data representation |
| Type | Describe shape or skewness of distribution |
| Difficulty | Easy -1.3 This is a straightforward histogram interpretation question requiring basic reading of frequency density, simple calculation (frequency = density × width), identification of positive skew from shape, and understanding of midrange with grouped data. All parts are routine recall and direct application with no problem-solving or novel insight required. |
| Spec | 2.02b Histogram: area represents frequency |
| Answer | Marks |
|---|---|
| Marks: M1, A1 | 2 |
| Answer | Marks |
|---|---|
| Marks: B1 | 1 |
| Answer | Marks |
|---|---|
| Marks: B1 Without wrong working, B1 Without wrong working | 2 |
## (i)
**Answer/Working:** $1000 \times 0.013 = 13$ or $0.2 \times 65 = 13$ or $0.2 \times 5 \times 13 = 13$
**Marks:** M1, A1 | 2
**Guidance:** Allow with or without working. For MR $1000 \times 0.13 = 130$ Allow M1A0. Allow M1A0 if extra terms added eg $(1000 \times 0.004)$. SC1 for $1000 \times 0.014 = 14$ For whole calculation
## (ii)
**Answer/Working:** Positive
**Marks:** B1 | 1
**Guidance:** Allow +ve but NOT skewed to the right. Do not allow 'positive correlation'
## (iii)
**Answer/Working:** Minimum value = 1500, Maximum value = 2500
**Marks:** B1 Without wrong working, B1 Without wrong working | 2
**Guidance:** Exact answers only unless good explanation such as eg no road has length zero so min is eg 1501. SC1 for lower and upper between 1499 and 1501 and upper between 2499 and 2501. Allow answer given as inequality
---In the Paris-Roubaix cycling race, there are a number of sections of cobbled road. The lengths of these sections, measured in metres, are illustrated in the histogram.
\includegraphics{figure_1}
\begin{enumerate}[label=(\roman*)]
\item Find the number of sections which are between 1000 and 2000 metres in length. [2]
\item Name the type of skewness suggested by the histogram. [1]
\item State the minimum and maximum possible values of the midrange. [2]
\end{enumerate}
\hfill \mbox{\textit{OCR MEI S1 2011 Q1 [5]}}