How many stomach cancer patients and controls would be required to estimate the difference in proportion of patients with sufficient concentrations of plasma antioxidant vitamins with a margin of...

How many stomach cancer patients and controls would be required to estimate the difference in proportion of patients with sufficient concentrations of plasma antioxidant vitamins with a margin of error not exceeding 5% using a 95% CI? The data in table 8-2 were reported recently from a similar study investigating the sufficiency of plasma antioxidant vitmians in throat cancer patients.