| Exam Board | Edexcel |
|---|---|
| Module | S2 (Statistics 2) |
| Year | 2008 |
| Session | January |
| Marks | 4 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Non-parametric tests |
| Type | Census vs sample decision |
| Difficulty | Easy -2.0 This is a straightforward recall question testing basic statistical terminology (census, sampling frame, sampling units) with minimal problem-solving. The context is simple and the answers are definitional, making it significantly easier than a typical A-level question that requires calculation or application of techniques. |
| Spec | 2.01a Population and sample: terminology2.01c Sampling techniques: simple random, opportunity, etc2.01d Select/critique sampling: in context |
| Answer | Marks | Guidance |
|---|---|---|
| (a) | A census is when every member of the population is investigated. | B1 |
| (b) | There would be no cookers left to sell. | B1 |
| (c) | A list of the unique identification numbers of the cookers. | B1 |
| (d) | A cooker. | B1 |
## Question 1:
**(a)** | A census is when every member of the population is investigated. | B1 | Need one word from group (1): every member/all items/entire; AND one word from group (2): population/collection of individuals/sampling frame. "Enumerating the population" on its own gets B0.
**(b)** | There would be no cookers left to sell. | B1 | Idea of tests to destruction. Do not accept "cheap" or "quick".
**(c)** | A list of the unique identification numbers of the cookers. | B1 | Idea of list/register/database of cookers/serial numbers.
**(d)** | A cooker. | B1 | cooker(s)/serial number(s). "The sample of 5 cookers" or "every 400th cooker" gets B1.
---\begin{enumerate}
\item (a) Explain what you understand by a census.
\end{enumerate}
Each cooker produced at GT Engineering is stamped with a unique serial number. GT Engineering produces cookers in batches of 2000. Before selling them, they test a random sample of 5 to see what electric current overload they will take before breaking down.\\
(b) Give one reason, other than to save time and cost, why a sample is taken rather than a census.\\
(c) Suggest a suitable sampling frame from which to obtain this sample.\\
(d) Identify the sampling units.\\
\hfill \mbox{\textit{Edexcel S2 2008 Q1 [4]}}