Stage 9 - Q1 - 2 marks
A survey concerns all 420 households. What is the population?
Hint
The population is everyone the conclusion concerns.
Stage 9 - Q2 - 2 marks
Select 48 households randomly from a full numbered list. Describe how.
Hint
Every listed member needs an equal chance and no repeated selection.
Stage 9 - Q3 - 2 marks
A group has 210 of 420 members. Allocate a sample of 48 proportionally.
Hint
Multiply the group share by the total sample size.
Stage 9 - Q4 - 2 marks
A group has 70 of 420 members. Allocate a sample of 48 proportionally.
Hint
Multiply the group share by the total sample size.
Stage 9 - Q5 - 3 marks
Three groups contain 210, 140 and 70 members. Allocate 48 sample places proportionally.
Hint
The three allocated counts must add to the required sample.
Stage 9 - Q6 - 4 marks
Groups contain 19, 15, 12 members. Allocate 12 places proportionally; use largest remainders after rounding down.
Hint
Do not round each count independently if that changes the total.
Stage 9 - Q7 - 3 marks
A sample matches the age proportions of households, but includes only online users. Is it necessarily representative?
Hint
Matching one characteristic does not guarantee coverage of another.
Stage 9 - Q8 - 3 marks
Is a survey of 192 volunteers necessarily better than a random sample of 48 households?
Hint
Separate sample size from selection method.
Stage 9 - Q9 - 4 marks
Each of the households has one assigned Junior/Senior group and one age band. What information is needed for a proportional sample across both factors?
Hint
A person belongs to both a location/time group and an age band.
Stage 9 - Q10 - 6 marks
Challenge: A population has 210 group A, 140 group B and 70 group C members. Design a sample of 48 that is proportional, random within groups and robust to non-response.
Hint
Solve allocation, selection and follow-up as three distinct design steps.