A. An ecologist had previously been studying the distribution of different types of deciduous trees in an alpine region in California before a large forest fire destroyed the area. She previously recorded exactly how many of each type of tree was present before the fire and currently is recording the new frequencies of tree types as they grow back. The ecologists is interested to see if the same relative distribution/frequencies of the tree types will grow again, or see if one type of tree will out grow the others and become more dominant then before. What hypothesis test should you run?

B. In Sub-Saharan Africa, more than half of mothers lose at least one child before the child's first birthday. Extensive data was collected from a sample of participants from the area, and researchers are looking for a significant relationship between infant mortality (in percent) and income level (in dollars). What hypothesis test should you run?

C. A researcher wants to investigate the effect of anti-anxiety medication on depression. To do so, she gives one group a placebo treatment and one group a dose of the medication and then measures depression levels in each group. What hypothesis test should you run?

D. Binge drinking on college campuses has been a hot topic in the popular media and in scholarly research. Flett, Goldstein, Wall, Hewitt, Wekerle, and Azzi (2008) report the results of a study relating perfectionism to binge drinking. In the study, students were classified into 3 groups based on the number of binge drinking episodes they experienced during the past month (0, 1, 2 or more). Researchers compared the level of parental criticism in each of the groups. What hypothesis test should you run?