| Exam Board | OCR MEI |
|---|---|
| Module | AS Paper 2 (AS Paper 2) |
| Year | 2018 |
| Session | June |
| Marks | 3 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Data representation |
| Type | Calculate frequency from frequency density |
| Difficulty | Easy -1.3 This is a straightforward histogram question testing basic understanding of frequency density. Part (i) requires simple arithmetic (dividing frequency by class width or multiplying frequency density by class width). Part (ii) tests recall of the definition that frequency density = frequency/class width, so the vertical axis should be 'frequency density' or 'runners per minute', not 'minutes per runner'. Both parts are routine with no problem-solving required. |
| Spec | 2.02b Histogram: area represents frequency |
| Time in minutes | \(15-\) | \(20-\) | \(25-\) | \(35-\) | \(45-60\) |
| Number of runners | 12 | 23 | 59 | 71 | |
| Frequency density | 2.4 | 5.9 | 7.1 | 1.4 |
| Answer | Marks | Guidance |
|---|---|---|
| 2 | (i) | Frequency density 4.6 |
| Number of runners 21 | B1 |
| Answer | Marks |
|---|---|
| [2] | 2.2a |
| Answer | Marks | Guidance |
|---|---|---|
| 2 | (ii) | Vertical axis should be labelled “number of |
| runners per minute” | E1 | |
| [1] | 2.3 | Or frequency density |
Question 2:
2 | (i) | Frequency density 4.6
Number of runners 21 | B1
B1
[2] | 2.2a
1.1
2 | (ii) | Vertical axis should be labelled “number of
runners per minute” | E1
[1] | 2.3 | Or frequency densityDoug has a list of times taken by competitors in a 'fun run'. He has grouped the data and calculated the frequency densities in order to draw a histogram to represent the information. Some of the data are presented in Fig. 2.
\begin{tabular}{|l|c|c|c|c|c|}
\hline
Time in minutes & $15-$ & $20-$ & $25-$ & $35-$ & $45-60$ \\
\hline
Number of runners & 12 & 23 & 59 & 71 & \\
\hline
Frequency density & 2.4 & & 5.9 & 7.1 & 1.4 \\
\hline
\end{tabular}
Fig. 2
\begin{enumerate}[label=(\roman*)]
\item Write down the missing values in the copy of Fig. 2 in the Printed Answer Booklet. [2]
\item Doug labels the horizontal axis on the histogram 'time in minutes' and the vertical axis 'number of minutes per runner'. State which one of these labels is incorrect and write down a correct version. [1]
\end{enumerate}
\hfill \mbox{\textit{OCR MEI AS Paper 2 2018 Q2 [3]}}