for joint prob distro

TABLE

NUMBER of crash

Age 0 1 2 3 TOTAL

31+ 0.63 0.07 0.03 0.02 0.75

30under .18 0.04 0.02 0.01 .25

Total .81 0.11 0.05 0.03 1.00

a For those 30 and under, what is Prob they have exactly 1 crash?

b. Irregardless of age, what is the expected amount of crashes in a year for one person randomly selected?

c. If told that 1 person has1 or more crashes per year what is approx probability they are 30 or under

assuming prob of 3 crash has prob of 0