Question

Olestra is a fat substitute approved by the FDA for use in snack foods. Because there have been anecdotal reports of gastrointestinal problems associated with olestra consumption, a randomized, double-blind, placebo-controlled experiment was carried out to compare olestra potato chips to regular potato chips with respect to GI symptoms. Among 522 individuals in the TG control group, 16.6% experienced an adverse GI event, whereas among the 562 individuals in the olestra treatment group, 14.8% experienced such an event.

(a) Calculate the test statistic and P-value. (Round your test statistic to two decimal places and your P-value to four decimal places.)

z = 0.81

P-value = ????

(b) If the true percentages for the two treatments were 20% and 30%, respectively, what sample sizes (m = n) would be necessary to detect such a difference with probability 0.90? (Round your answer up to the nearest whole number.)

Answer 1