Participants in a study of a new medication received either medication a or a placebo. find p(placebo and improvement). you may find it to make a tree diagram of the problem on a separate piece of paper.

of all those who participated in the study, 80% received medication a.

of those who received medication a, 76% reported an improvement.

of those who received the placebo, 62% reported no improvement.

i don't know how to do this at all, any hints or would be nice. : )