describe basic probability  set theory
In a survey conducted to realise how long Americans keep their cars 2000 automobile owners were asked how long they plan to keep their present cars. The consequences of the survey follow. What is the probability distribution associated with these data.
Years Car Is Kept, x

Respondents

Probability

0 ≤x < 1

70

[ ]

1 ≤x < 3

450

[ ]

3 ≤x < 5

295

[ ]

5 ≤x < 7

350

[ ]

7 ≤x < 10

245

[ ]

10 ≤ x

590

[ ]

describe the probability that an automobile owner selected at random from those surveyed plans to keep his or her present car
1) Less than five yr?
2) 3 yr or more?