1. 1
   A supermarket manager wants to find out how satisfied customers are with the new self-checkout tills. She plans to ask every 10th customer who leaves the store on a Tuesday morning to fill in a short questionnaire.

   (a)

   What name is given to this sampling method?

   [1 mark]

   • AStratified sampling
   • BSystematic sampling
   • CQuota sampling
   • DOpportunity sampling

   (b)

   The manager only surveys customers on a Tuesday morning. Which of these is the main weakness of her sampling method?

   [1 mark]

   • ATuesday morning shoppers may not represent all customers, for example those who shop at weekends
   • BSystematic sampling can never be used for customer opinions
   • CEvery 10th customer is too large a sample to be useful
   • DSelf-checkout users cannot be asked about satisfaction

   (c)

   The manager decides the data she collects (satisfaction ratings from 1 to 5) is which type of data?

   [1 mark]

   • AContinuous
   • BBivariate
   • CQualitative
   • DDiscrete

   Total for question 1: 3 marks

2. 2
   A school has 840 students: 350 in Key Stage 3, 310 in Key Stage 4 and 180 in Key Stage 5. The head teacher wants a stratified sample of 84 students to survey about the school canteen.

   (a)

   Calculate the number of Key Stage 4 students that should be in the sample.

   [2 marks]

   (b)

   State one advantage of using stratified sampling rather than simple random sampling for this survey, giving a reason based on the school's student numbers.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A charity wants to estimate the number of foxes living in a large park. On Monday, volunteers catch 40 foxes, tag each one, and release them back into the park. A week later, they catch a new sample of 60 foxes and find that 8 of them are tagged.

   (a)

   Using the capture-recapture method, estimate the total number of foxes in the park.

   [3 marks]

   (b)

   Explain why the capture-recapture method might give an unreliable estimate if some tagged foxes died between the two sampling occasions.

   [3 marks]

   Total for question 3: 6 marks

4. 4
   A researcher is designing a questionnaire to find out how many hours per week people spend exercising. One of her draft questions is:
   
   "Don't you agree that most people exercise for less than 5 hours a week?"

   (a)

   Give two criticisms of this question and explain why each is a problem for collecting reliable data.

   [4 marks]

   (b)

   Rewrite the researcher's question as a single, well-designed question with response options, so that it avoids the criticisms you identified and would collect data that is easy to analyse.

   [4 marks]

   (c)

   The researcher decides instead to collect secondary data from a national government survey on exercise habits, rather than running her own primary survey.
   
   Evaluate this decision by giving one advantage and one disadvantage of using secondary data instead of primary data for her investigation.

   [5 marks]

   Total for question 4: 13 marks

End of questions