Mrs. Bergstedt teaches four periods, each with 15 students. The first period class has 9 juniors, the second period class has 12 juniors, the third period class has 6 juniors, and the fourth period class has 3 juniors.

She is going to randomly choose four students to present a project, one student from each period. What is the probability that she chooses exactly 3 juniors, given that she MUST choose juniors from classes two and four? [Round to the nearest hundredth.]