The Comittee on student Life at a university conducted a survey of 375 undergraduate students

regarding satisfaction with student government. Results of the survey are shown on table by class rank

Freshman.|.Sophomore.|Junior..|Senior.… Total..
..Satisfied...57.....| ...49.. ..|.....64..|....61..|. 231....
..Neutral.....23.....| .....15.. ..|...16....|..11....|. 65.....
..Not Satis..21.....|... ...18. ..|....14....|...26...|. 79.....
..Total........101.....|. ....82. ...|....94...|..98...|. 375....

If a survey participant is selected at random, what is the probability that he or she is satisfied or is a junior?

n(satisfied) + n(junior) - n(both) = 231+ 94 - 64 = 261

Pr = 261/375 = 0.696 <---------