Suppose that about 20% of students in school have used marijuana in the last year. In order to preserve anonymity during surveys, a technique called randomized response is often used. A student is approached and asked to flip a coin but not show it to the interviewer. If the coin is heads, the student answers the question: "Was your mother born in January to June (inclusive)?" If the coin is tails, the student answers the question: "Have you used marijuana in the last year?" Because the interviewer does not know the outcome of the coin flip, the students' responses are confidential. What is the probability then that if a yes is received, the student used marijuana in the last year? (a) 0.20 (b) 0.10 (c) 0.25 (d) 0.28 1 out OH This is correct. Text reference: Section 10.4 Tree Diagrams