A psychologist believes that people raised in rural areas will be more likely to help in an emergency than people raised in metropolitan areas. Her rationale is that people raised in rural areas must depend upon each other more for survival and they tend to socialize more with the local community. The psychologist randomly selects 40 people who were raised in a metropolitan area and 40 people raised in a rural community and compares them to a test of altruism.

Which test is appropriate for this data?