How am I able to find the true proportion-based on such minimal information? What am I supposed to derive from this?

Records of a university (collected over many years} show that on average, 74% of all incoming students have I.Q.'s of at least 115. Of course, the percentage varies somewhat year to year, and this variation is measured by a standard deviation of 3 percent. If a sample check of 30 freshmen entering the university in 2018 showed that only 18 of them have I.Q.'s of at least 115, estimate the true proportion of students with I.Q.'s of at least 115 in that freshman class by: (1a) using only the prior information; {lb} using only the 2018 data; (1c) combining the prior information with the 2018 data. Hint: First show that the parameters of the beta distribution can he expressed in terms of ,u and 02, where a is the mean and 32 the variance of the beta distribution, as follows: (paw) Haw1). U2