An experiment involves placing a single worm on a plate. After 3 days, there are no worms with probability 0.1, one worm with probability 0.35, two worms with probability 0.15, three worms with probability 0.3, and four worms with probability 0.1.
a. Sketch the probability distribution.
b. Sketch the cumulative distribution.
c. Find the expected number of worms.
d. What does this mean?