Four kinds of agent, one case at a time. Turn over the clues one by one and watch the odds move across virus, fungus, protozoan, and worm. Then commit, and see whether the reasoning held.
On the slide
Turn over a clue to see what the laboratory finds.
How likely is each one now?
Each clue multiplies the odds up or down. A clue that rules a group out drops it to zero and it never comes back.
Case 1 of 8turn over the clues
Your call
Commit whenever you are ready. You do not have to use every clue.