The article “National Geographic, the Doomsday Machine,” which appeared in the March 1976 issue of the Journal of Irreproducible Results (yes, there really is a journal by that name—it’s a spoof of technical journals!) predicted dire consequences resulting from a nationwide buildup of National Geographic magazines. The author’s predictions are based on the observation that the number of subscriptions for National Geographic is on the rise and that no one ever throws away a copy of National Geographic. A key to the analysis presented in the article is the weight of an issue of the magazine. Suppose that you were assigned the task of estimating the average weight of an issue of National Geographic. How many issues should you sample to estimate the average weight to within 0.1 oz with 95% confidence? Assume that σ is known to be 1 oz.