Let x be the amount won or lost in betting $5 on red in roulette. then px(5) = 18 38 and px(−5) = 20 38. if a gambler bets on red one hundred times, use the central limit theorem to estimate the probability that those wagers result in less than $50 in losses. larsen, richard j.. an introduction to mathematical statistics and its applications (p. 247). pearson education. kindle edition.