A college investigates every student's journey time. What data collection method is this?
stratum sizepopulation size×total sample size\frac{\text{stratum size}}{\text{population size}}\times\text{total sample size}population sizestratum size×total sample size
25, since 300720×60=25\frac{300}{720}\times60=25720300×60=25.
A census.
A representative sample reflects the population's relevant characteristics, while a sampling frame is the list from which units are selected.
2.1.3 Sampling techniques Flashcards
Flashcards for OCR A Level Maths 2.1.3 Sampling techniques, covering the key formulae, methods and definitions you need to recall for Paper 1, Paper 2 and Paper 3. 24 cards, matched to the OCR A Level Maths (H240) specification. Recall questions account for roughly 50% of marks at A Level Maths, so these target the marks you can secure before the paper starts.