A study comparing the working hours between Americans and Canadians took simple random samples of employees from each country and asked them how many hours per week they worked in their jobs. In the sample of 140 Americans, the average hours per week was 36.6 with a standard deviation of 5.6 hours, and in the sample of 140 Canadians, the average hours per week was 37.4 with a standard deviation of 4.9 hours.
Test the claim, at significance level 0.05, that Americans and Canadians work the same number of hours per week on average.

Write the null and alternative hypotheses for this hypothesis test.