A team of marine biologists is investigating whether the location of blue mussel (Mytilus edulis) beds relative to industrial ports affects the concentration of microplastic particles in their tissue.
An opportunity sample of thirty mussels was harvested from two distinct habitats. Fifteen mussels were gathered from a bed near a busy commercial shipping port (Port-adjacent group), and fifteen mussels were gathered from a bed in a designated marine conservation zone (Conservation group).
The soft tissue of each mussel was fully digested in a laboratory, and the number of microplastic particles per individual was counted using high-resolution fluorescence microscopy.
The descriptive statistics for the microplastic particle counts in each group were:
Name an appropriate non-parametric test that the researchers could use to analyse whether there is a significant difference in microplastic counts between the two groups.
121 exam-style questions on AQA A Level Psychology Inferential testing (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.