1 2 3 4 An experiment can result in one or both of events A

1)

2)

3)

4)

An experiment can result in one or both of events A and B with the probabilities shown in this probability table. Ac A 0.31 0.49 0.15 0.05 B 0.15 0.05 Find the following probabilities. (Round your answers to three decimal places when necessary.) (a) P(A) 0.46 (b) P(B) 0.80 (c) PA n B) 0.31 (d) PIA U B) 0.95 (e) P(AlB) 675

Solution

(1)(f) P(B|A)= P(A and B)/P(B) =0.31/0.46 =0.673913

---------------------------------------------------------------------------------------------------------------

(2)(c) 4/70 = 0.05714286

---------------------------------------------------------------------------------------------------------------

(3)(c)(1/9) + (1/9) - (1/9)*(1/9) = 2/9 - 1/81 = 17/81

---------------------------------------------------------------------------------------------------------------

(4) 0.4*0.45+0.3*0.3 = 0.27

i.e. 27%