Researchers have conducted a study to investigate the mathematical competency of primary school students from three different countries: Australia, Canada and America. It was hypothesised that...

Researchers have conducted a study to investigate the mathematical competency of primary school students from three different countries: Australia, Canada and America. It was hypothesised that mathematical competency would be highest for Canadian students, followed by Australian students, then American students. It was also hypothesised that the child's sex would moderate this relationship. Here, mathematical competency is measured on a continuous scale, with higher scores representing higher levels of competency.

Which of the following would be an appropriate statistical test to conduct, which addresses these hypotheses?