De Moivre’s solution was published as a Latin pamphlet dated 13 November 1733. Introducing his translation of, and comments on, this work at the end of the last edition of The Doctrine of Chances, he took “the liberty to say, that this is the hardest Problem that can be proposed on the Subject of Chance” (p. 242). In this problem the probability of getting exactly m successes in n trials is expressed by the m th term in the expansion of (a + b)n—that is, ambn−m, where a is the given ratio of chances and b = 1 − a. Hence the probability of obtaining a proportion of successes lying between the two limits is a problem in “approximating the Sum of the Terms of the Binomial (a + b)n expanded into a Series” (p. 243).