Astudy considered whether daily consumption of garlic could reduce tick bites. the study used a crossover design where half of the subjects used placebo first and garlic second and half the reverse. the authors described garlic being more effective with 62 subjects and placebo being more effective with 46 subjects. does this suggest a real difference between garlic and placebo, or are the results consistent with random variation?

a. find the test statistic value.

b. find the p-value.