| Exam Board | OCR MEI |
|---|---|
| Module | Paper 2 (Paper 2) |
| Year | 2019 |
| Session | June |
| Marks | 9 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Bivariate data |
| Type | Interpret census or real-world data |
| Difficulty | Moderate -0.8 This is a straightforward data interpretation question requiring basic statistical knowledge: checking outliers using the 1.5×IQR rule (standard A-level formula), a simple percentage calculation for deaths, and contextual explanation of why older populations have higher death rates. All parts are routine applications with no problem-solving or novel insight required. |
| Spec | 2.01a Population and sample: terminology2.02f Measures of average and spread2.02g Calculate mean and standard deviation |
| Europe | Africa | |
| \(n\) | 48 | 56 |
| minimum | 6.28 | 3.58 |
| lower quartile | 8.50 | 7.31 |
| median | 9.53 | 8.71 |
| upper quartile | 11.41 | 11.93 |
| maximum | 14.46 | 14.89 |
| Answer | Marks | Guidance |
|---|---|---|
| Answer | Marks | Guidance |
| The data was not available for all countries oe | B1 |
| Answer | Marks | Guidance |
|---|---|---|
| Answer | Marks | Guidance |
| Use of \(Q_1 - 1.5\times(Q_3 - Q_1)\) and \(Q_3 + 1.5\times(Q_3 - Q_1)\), seen for either set | M1 | |
| \(4.135 < 6.28\) and \(15.775 > 14.46\) | A1 | if A0A0 allow SC1 for 4.135, 15.775, 0.38 and 18.86 all seen |
| \(0.38 < 3.58\) and \(18.86 > 14.89\) | A1 |
| Answer | Marks | Guidance |
|---|---|---|
| Answer | Marks | Guidance |
| \(22\,954\) isw | B1 | allow 22 955, 22 950 or 23 000; NB \(6411776 \times \dfrac{3.58}{1000}\) |
| Answer | Marks | Guidance |
|---|---|---|
| Answer | Marks | Guidance |
| There are almost certainly more "old" people in the population oe | B1 |
| Answer | Marks | Guidance |
|---|---|---|
| Answer | Marks | Guidance |
| In African countries there is a negative association/relationship between (or negative correlation between the ranks of) median age and crude death rate, but in Europe there seems to be a positive association/relationship between (or positive correlation between the ranks of) median age and crude death rate | B1 | do not allow "negative correlation" and/or "positive correlation"; comment comparing and contrasting type of relationship in both continents for B1, and one comment comparing and contrasting strength of relationship in both continents for B1 |
| The "association"/"relationship between" or "correlation between the ranks of" median age and crude death rate (appears to be) stronger in Europe | B1 | allow B1 both relationships are weak oe; allow equivalent explanations in words eg as median age increases crude death rates decrease in Africa and similar for Europe |
## Question 14(a):
| Answer | Marks | Guidance |
|--------|-------|----------|
| The data was not available for all countries oe | B1 | |
---
## Question 14(b):
| Answer | Marks | Guidance |
|--------|-------|----------|
| Use of $Q_1 - 1.5\times(Q_3 - Q_1)$ and $Q_3 + 1.5\times(Q_3 - Q_1)$, seen for either set | M1 | |
| $4.135 < 6.28$ and $15.775 > 14.46$ | A1 | if **A0A0** allow **SC1** for 4.135, 15.775, 0.38 and 18.86 all seen |
| $0.38 < 3.58$ and $18.86 > 14.89$ | A1 | |
---
## Question 14(c):
| Answer | Marks | Guidance |
|--------|-------|----------|
| $22\,954$ isw | B1 | allow 22 955, 22 950 or 23 000; **NB** $6411776 \times \dfrac{3.58}{1000}$ |
---
## Question 14(d):
| Answer | Marks | Guidance |
|--------|-------|----------|
| There are almost certainly more "old" people in the population oe | B1 | |
---
## Question 14(e):
| Answer | Marks | Guidance |
|--------|-------|----------|
| In African countries there is a negative association/relationship between (or negative correlation between the ranks of) median age and crude death rate, but in Europe there seems to be a positive association/relationship between (or positive correlation between the ranks of) median age and crude death rate | B1 | do not allow "negative correlation" and/or "positive correlation"; comment comparing and contrasting type of relationship in both continents for **B1**, **and** one comment comparing and contrasting strength of relationship in both continents for **B1** |
| The "association"/"relationship between" or "correlation between the ranks of" median age and crude death rate (appears to be) stronger in Europe | B1 | allow **B1** both relationships are weak oe; allow equivalent explanations in words eg as median age increases crude death rates decrease in Africa and similar for Europe |
---14 The pre-release material includes data concerning crude death rates in different countries of the world. Fig. 14.1 shows some information concerning crude death rates in countries in Europe and in Africa.
\begin{table}[h]
\begin{center}
\begin{tabular}{ | l | c | c | }
\hline
& Europe & Africa \\
\hline
$n$ & 48 & 56 \\
\hline
minimum & 6.28 & 3.58 \\
\hline
lower quartile & 8.50 & 7.31 \\
\hline
median & 9.53 & 8.71 \\
\hline
upper quartile & 11.41 & 11.93 \\
\hline
maximum & 14.46 & 14.89 \\
\hline
\end{tabular}
\captionsetup{labelformat=empty}
\caption{Fig. 14.1}
\end{center}
\end{table}
\begin{enumerate}[label=(\alph*)]
\item Use your knowledge of the large data set to suggest a reason why the statistics in Fig. 14.1 refer to only 48 of the 51 European countries.
\item Use the information in Fig. 14.1 to show that there are no outliers in either data set.
The crude death rate in Libya is recorded as 3.58 and the population of Libya is recorded as 6411776.
\item Calculate an estimate of the number of deaths in Libya in a year.
The median age in Germany is 46.5 and the crude death rate is 11.42. The median age in Cyprus is 36.1 and the crude death rate is 6.62 .
\item Explain why a country like Germany, with a higher median age than Cyprus, might also be expected to have a higher crude death rate than Cyprus.
Fig. 14.2 shows a scatter diagram of median age against crude death rate for countries in Africa and Fig. 14.3 shows a scatter diagram of median age against crude death rate for countries in Europe.
\begin{figure}[h]
\begin{center}
\includegraphics[alt={},max width=\textwidth]{95eb3bcc-6d3c-4f7e-9b27-5e046ab57ec5-10_678_1221_1975_248}
\captionsetup{labelformat=empty}
\caption{Fig. 14.2}
\end{center}
\end{figure}
\begin{figure}[h]
\begin{center}
\includegraphics[alt={},max width=\textwidth]{95eb3bcc-6d3c-4f7e-9b27-5e046ab57ec5-11_588_1248_223_228}
\captionsetup{labelformat=empty}
\caption{Fig. 14.3}
\end{center}
\end{figure}
The rank correlation coefficient for the data shown in Fig. 14.2 is - 0.281206 .\\
The rank correlation coefficient for the data shown in Fig. 14.3 is 0.335215 .
\item Compare and contrast what may be inferred about the relationship between median age and crude death rate in countries in Africa and in countries in Europe.
\end{enumerate}
\hfill \mbox{\textit{OCR MEI Paper 2 2019 Q14 [9]}}