A study conducted in Uganda and Kenya looked at heterosexual couples in which one of the partners was HIV-positive and the other was not. The person in each couple who was not HIV-positive was randomly assigned to one of three study regimens: tenofovir (TDF), combination teno fovir-emtricitabine (TDF-FTC), or placebo and was followed for up to 36 months. Seventeen of the 1584 people assigned to TDF became positive for HIV, as did 13 of the 1579 assigned to TDF- FTC and 52 of the 1584 assigned to the placebo.
a. Find the percentage in each group in the sample that became HIV positive, and compare these percentages.
b. Create a two-way table with the treatment labels across the top.
c. Test the hypothesis that treatment and HIV status are associated using a significance level of 0.05.