According to government data, the probability that an adult was never in a museum is 15%. in a random survey of 10 adults, what is the probability that two or fewer were never in a museum? round to the nearest thousandth.

Let p be the probability that an adult was never in a museum. Hence p = 0.15. Then q is the probability that an adult was in a museum is 1 - 0.15 = 0.75. We have a binomial expansion where the probability of k success in n trials is given by P_n (k) = (n, k) p^ (k) q^ (n - k) where (n, k) is the number of ways to select 10 objects from k things. At least two or fewer means we have P_10 (< or equal to 2) So we have P_10 (less than or equal to 2) = P_10 (0) + P_10 (1) + P_10 (2). So we have P _10 (0) = (10, 0) (0.15) ^ (0) (0.75) ^ (0) = 0.196. For P_10 (1), we have 0.3474 and for P_10 (2), we have 0.2758. Adding these we have 0.1960 + 0.3474 + 0.2758 = 0.8192.