The researchers recruited 917 patients who had tested positive for Staphylococcus aureus and randomly assigned them to receive a nasal ointment that contained either a staph-killing solution or a placebo. Post-surgery infections with S. Aureus were then recorded. In the treatment, group, 17 of 504 patients developed a staph infection, compared with 32 of 413 patients in the placebo group.

Is there good evidence that treatment of staph-positive patients before surgery reduces the rate of post-surgical staph infection? State the null and alternative hypotheses, find the test statistic, and use either software or the bottom row of Table C for the P-value.