The NSW container deposit scheme, Return and Earn is the largest litter reduction scheme introduced in NSW. Return and Earn began rolling out across NSW on 1 December 2017 in response to the Premier's goal of reducing the volume of litter in the state by 40% by 2020. At the time, drink container litter made up 44% of the volume of all litter in the state and cost more than $162 million to manage.

Since commencement, the scheme has been a resounding success, reducing container litter in the environment and boosting recycling. In 2020 there was a 52% reduction in the volume of eligible container litter in NSW, and over 300,000 tonnes of materials recycled.

Ryde City Council wanted to investigate the impact of Return and Earn in its council area. A random sample of household from the council area was selected to participate in a study and they were asked to answer a series of questions about their recycling habits and their use of Return and Earn.

The council statistician was asked to analyse the data to answer the following research question:

Research Question: "Is the average volume of litter (in tonnes) in Ryde Council Area differ between the owners of standalone houses and apartment units?

a. (2 marks) Based on the research question, which variables are needed for analysis? Name at least two variables and identify their variable types.

b. (1 mark) How would you suggest data to be recorded? (hint: what would be in the rows, what would be in the columns in an Excel file)

c. (2 marks) What would be the most appropriate test for this data? Explain briefly why.