An environmental engineer is investigating whether a new bio-filtration system reduces the concentration of nitrates in runoff water compared to a standard sand-filter system. They set up 24 test plots, randomly assigning 12 to use the bio-filtration system and 12 to use the standard sand-filter system. After a simulated rainfall event, they measure the nitrate concentration in the runoff from each plot in parts per million (ppm).
Suggest an appropriate statistical test the engineer could use to analyse the data. Justify your choice of test.
Practise AQA A Level Psychology Inferential testing (A-level only) with exam-style questions for A Level Psychology. 123 questions, matched to the AQA A Level Psychology (7182) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.
