Let the mean and variance of \( 7 \) observations \( 2, 4, 10, x, 12, 14, y \), \( x > y \), be \( 8 \) and \( 16 \) respectively. Two numbers are chosen from \( \{1, 2, 3, x - 4, y, 5\} \) one after another without replacement, then the probability, that the smaller number among the two chosen numbers is less than \( 4 \), is: