| Exam Board | OCR MEI |
|---|---|
| Module | S1 (Statistics 1) |
| Marks | 8 |
| Paper | Download PDF ↗ |
| Topic | Measures of Location and Spread |
| Type | Skewness identification and interpretation |
| Difficulty | Easy -1.2 This is a straightforward S1 question requiring basic statistical skills: identifying skewness from a stem-and-leaf diagram (visual inspection), calculator use for mean/SD, and applying the standard outlier rule (Q1-1.5×IQR, Q3+1.5×IQR). All parts are routine recall and application of standard procedures with no problem-solving or conceptual depth required. |
| Spec | 2.02f Measures of average and spread2.02g Calculate mean and standard deviation2.02h Recognize outliers |
| 3 | 4 | 6 | 7 | 8 | 9 | 9 | ||
| 4 | 0 | 2 | 2 | 3 | 4 | 6 | 8 | 9 |
| 5 | 0 | 1 | 3 | 5 | 8 | |||
| 6 | 2 | 4 | 5 | |||||
| 7 | 4 | 6 | ||||||
| 8 | 1 |
1 The stem and leaf diagram illustrates the heights in metres of 25 young oak trees.
\begin{center}
\begin{tabular}{ l | l l l l l l l l }
3 & 4 & 6 & 7 & 8 & 9 & 9 & & \\
4 & 0 & 2 & 2 & 3 & 4 & 6 & 8 & 9 \\
5 & 0 & 1 & 3 & 5 & 8 & & & \\
6 & 2 & 4 & 5 & & & & & \\
7 & 4 & 6 & & & & & & \\
8 & 1 & & & & & & & \\
\end{tabular}
\end{center}
Key: 4 |2 represents 4.2\\
(i) State the type of skewness of the distribution.\\
(ii) Use your calculator to find the mean and standard deviation of these data.\\
(iii) Determine whether there are any outliers.
\hfill \mbox{\textit{OCR MEI S1 Q1 [8]}}