Question: Herbal cancer. A report in the New England Journal of Medicine (June 6, 2000) notes growing evidence that the herb Aristolochia fangchi can cause urinary tract cancer in those who take it. Suppose you are asked to design an experiment to study this claim. Imagine that you have data on urinary tract cancers in subjects who have used this herb and similar subjects who have not used it and that you can measure incidences of cancer and precancerous lesions in these subjects. State the null and alternative hypotheses you would use in your study.