Consider a collection of 15 balls, 5 of which are octarine. If we have 15 balls divided into two groups, using an unknown system of making these groups, and Group 1 has 4 balls and Group 2 has 11 balls. If the groups are created randomly, without reference to ball colour, what is the probability of 3 of the 5 octarine balls ending up in Group 1? Round your answer to five decimal places.