\[X \sim Binomial(n, p)\]
Where \(X=\) number of successes (green jelly beans) out of \(n=20\) trials. The (population) parameter here is \(p = 0.15\), the probability of drawing a green jelly bean (or, equivalently, the proportion of green jelly beans in the entire population of the large bowl of jelly beans).
In class, we observed \(24\) different values for \(X\), i.e. \(x_1, x_2, \dots, x_{24}\), which we plotted in the dot plot below: