You are given that in one town, 73% of adults have health insurance. You are asked to find the probability that 9 adults selected at random from the town all have health insurance.
The problem clearly made a condition that after a random sample, all 9 adults that are selected must have an insurance. Therefore, there are 9 out of 9 people in the town who has health insurance. The 73% will then be multiplied 9 times because only 73% of the adult in town has health insurance.
P (9 of 9 have health insurance) = 0.73⁹
P (9 of 9 have health insurance) = 0.05887
P (9 of 9 have health insurance) = 5.89%