WeBWorK Standalone Renderer

Let X be a discrete random variable that denotes the number of junk e-mail messages received in a day. A web site developer estimates that the probability function for X is:

$\begin{array}{c|c} x & P(X=x) \\ \hline 0 & \\ 1 & \\ 2 & \\ 3 & \\ 4 & \\ 5 & \\ 6 & \\ \end{array}$

Answer the following questions, rounding your answers to two decimal places where appropriate.

(a) What is the probability that the number of junk e-mail messages is less than or equal to 2, $P(X \le 2)$ ?

(b) What is the probability that the number of junk e-mail messages is greater than 4?

(c) What is the probability that at least one junk e-mail message will be received in a day?

You can earn partial credit on this problem.