An epidemiologist wants to evaluate the association between skin cancer incidence and the risk factors such as sun exposure. He decided to compare skin cancer rates in Costa Rica to skin cancer rates in Norway. He hypothesized that Costa Rica, being closer to the equator and receiving relatively larger amounts of UV radiation from sunlight exposure, would have significantly higher skin cancer incidence rates. This study design is:

Not all members of the radio audience of orson welles' war of the worlds broadcast panicked immediately. indeed, some didn't panic until they looked out of the window and saw empty streets; others didn't panic until they saw streets full of traffic. it was after checking out the situation that these citizens decided that the martians had indeed invaded earth. this example illustrates that contagion can result when people look to others for the interpretation of ambiguous situations . can result when cultural norms reinforce people's most likely responses. occurs primarily because humans are by nature irrational creatures. is especially likely when people are motivated to make independent decisions.