A researcher sends a postal questionnaire to 500 randomly selected households in a town, asking about attitudes to a new recycling scheme. 145 questionnaires are returned completed. The researcher notices that most of the returned questionnaires come from streets with older, detached houses, with very few returned from streets with flats and rented housing. [This is a hypothetical scenario, written for this exercise.]
Using your knowledge of response rates and representativeness, explain what is happening in this scenario, including the response rate as a percentage.
(Total for Question 12 is 6 marks)