Draw trees representing the sequence of experiments.
1. Experiment I is performed. Outcome a occurs with probability .4, and outcome b occurs with probability .6. Then experiment II is performed. Its outcome c occurs with probability .8, and its outcome d occurs with probability .2.
2. Experiment I is performed twice. The three outcomes of experiment I are equally likely.
3. A training program is used by a corporation to direct hirees to appropriate jobs. The program consists of two steps. Step I identifies 30% as management trainees, 60% as non-managerial workers, and 10% to be transferred to a different department. In step II, 75% of the management trainees are assigned to managerial positions, 20% are assigned to non-managerial positions, and 5% are transferred. In step II, 60% of the non-managerial workers are kept in the same category, 10% are assigned to management positions, and 30% are transferred.
4. An accounting firm uses a two-step auditing procedure to find problems in erroneous tax returns. Step I identifies the problem in the tax return with probability .7. Step II (which is executed only if step I fails to locate the problem) identifies the problem with probability .6?