Chapter 4, Problem 26P

Use the following information to answer the next five exercises: A physics professor wants to know what percent of physics majors will spend the next several years doing post-graduate research. He has the following probability distribution.

Table 4.27

x	P(x)	xP(x)
1	0.35
2	0.20
3	0.15
4
5	0.10
6	0.05

Find the probability that a physics major will do paot-graduate research for at most three year, $P\left(x\le 3\right)=\_\_\_$