Fig. 16.1, Fig. 16.2 and Fig. 16.3 show some data about life expectancy, including some from the pre-release data set.

\includegraphics{figure_16_1}
\includegraphics{figure_16_2}
\includegraphics{figure_16_3}

\begin{enumerate}[label=(\alph*)]
\item Comment on the shapes of the distributions of life expectancy at birth in 2014 and 1974. [2]
\item 
\begin{enumerate}[label=(\roman*)]
\item The minimum value shown in the box plot is negative. What does a negative value indicate? [1]
\item What feature of Fig 16.3 suggests that a Normal distribution would not be an appropriate model for increase in life expectancy from one year to another year? [1]
\item Software has been used to obtain the values in the table in Fig. 16.3. Decide whether the level of accuracy is appropriate. Justify your answer. [1]
\item John claims that for half the people in the world their life expectancy has improved by 10 years or more. Explain why Fig. 16.3 does not provide conclusive evidence for John's claim. [1]
\end{enumerate}
\item Decide whether the maximum increase in life expectancy from 1974 to 2014 is an outlier. Justify your answer. [3]
\end{enumerate}

Here is some further information from the pre-release data set.

\begin{tabular}{|l|c|}
\hline
Country & Life expectancy at birth in 2014 \\
\hline
Ethiopia & 60.8 \\
\hline
Sweden & 81.9 \\
\hline
\end{tabular}

\begin{enumerate}[label=(\alph*)]
\setcounter{enumi}{3}
\item 
\begin{enumerate}[label=(\roman*)]
\item Estimate the change in life expectancy at birth for Ethiopia between 1974 and 2014.
\item Estimate the change in life expectancy at birth for Sweden between 1974 and 2014.
\item Give one possible reason why the answers to parts (i) and (ii) are so different. [4]
\end{enumerate}
\end{enumerate}

Fig. 16.4 shows the relationship between life expectancy at birth in 2014 and 1974.

\includegraphics{figure_16_4}

A spreadsheet gives the following linear model for all the data in Fig 16.4.

(Life expectancy at birth 2014) = 30.98 + 0.67 × (Life expectancy at birth 1974)

The life expectancy at birth in 1974 for the region that now constitutes the country of South Sudan was 37.4 years. The value for this country in 2014 is not available.

\begin{enumerate}[label=(\alph*)]
\setcounter{enumi}{4}
\item 
\begin{enumerate}[label=(\roman*)]
\item Use the linear model to estimate the life expectancy at birth in 2014 for South Sudan. [2]
\item Give two reasons why your answer to part (i) is not likely to be an accurate estimate for the life expectancy at birth in 2014 for South Sudan. You should refer to both information from Fig 16.4 and your knowledge of the large data set. [2]
\end{enumerate}
\item In how many of the countries represented in Fig. 16.4 did life expectancy drop between 1974 and 2014? Justify your answer. [3]
\end{enumerate}

\hfill \mbox{\textit{OCR MEI Paper 2  Q16 [20]}}