Probability Distribution Function (PDF) for a Discrete Random Variable · Exercise 6

A baker is deciding how many batches of muffins to make to sell in his bakery. He wants to make enough to sell every one and no fewer. Through observation, the baker has established a probability distribution.
$$\begin{array}{cc}\text{x}& \text{P(x)}\\ \text{1}& \text{.15}\\ \text{2}& \text{.35}\\ \text{3}& \text{.40}\\ \text{4}& \text{.10}\end{array}$$

Define the random variable X.

Its source prints no answer for this problem, so there's nothing to check against.

OpenStax, Statistics · §4.1 Probability Distribution Function (PDF) for a Discrete Random Variable · Exercise 6