Easy -1.8 This is a straightforward recall question asking for a basic description of simple random sampling procedure. It requires only knowledge of what constitutes random sampling (e.g., numbering items 1-1000 and using random number generator) with no calculation, problem-solving, or statistical reasoning beyond the definition.
List needn't be stated, but must mention CDs. Assume sequential unless stated otherwise.
Select using random numbers
B1
*Not* "select numbers randomly". Hat, etc: B1B0. If "number CDs randomly", B1 max unless "sort by number". Systematic: 66 or 67 B1, random start B1. Stratified: apply scheme
[2]
## Question 1:
| Answer | Marks | Guidance |
|--------|-------|----------|
| Number CDs (sequentially) | B1 | List needn't be stated, but must mention CDs. Assume sequential unless stated otherwise. |
| Select using random numbers | B1 | *Not* "select numbers randomly". Hat, etc: B1B0. If "number CDs randomly", B1 max unless "sort by number". Systematic: 66 or 67 B1, random start B1. Stratified: apply scheme |
| | **[2]** | |
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1 In one day's production, a machine produces 1000 CDs . Explain how to take a random sample of 15 CDs chosen from one day's production.
\hfill \mbox{\textit{OCR S2 2012 Q1 [2]}}