Chapter 9.1, Problem 16E

Using Probability Distributions In Exercises 15–18, sketch a graph of the probability distribution and find each probability.

x	0	1	2	3	4	5
P(x)	$\frac{10}{30}$	$\frac{8}{30}$	$\frac{6}{30}$	$\frac{3}{30}$	$\frac{2}{30}$	$\frac{1}{30}$

(a) $P\left(1\le x\le 4\right)$

(b) $P\left(x\le 4\right)$