Consider the following contingency table.



B Bc
A 20 12
Ac 50 18

a. Convert the contingency table into a joint probability table. (Round intermediate calculations to at least 4 decimal places and final answer to 4 decimal places.)

b. What is the probability that A occurs? (Round intermediate calculations to at least 4 decimal places and final answer to 4 decimal places.)

c. What is the probability that A and B occur? (Round intermediate calculations to at least 4 decimal places and final answer to 4 decimal places.)

d. Given that B has occurred, what is the probability that A occurs? (Round intermediate calculations to at least 4 decimal places and final answer to 4 decimal places.)

e. Given that Ac has occurred, what is the probability that B occurs? (Round intermediate calculations to at least 4 decimal places and final answer to 4 decimal places.)

f. Are A and B mutually exclusive events?

multiple choice 1
Yes because P(A | B) ≠ P(A).
Yes because P(A ∩ B) ≠ 0.
No because P(A | B) ≠ P(A).
No because P(A ∩ B) ≠ 0.

g. Are A and B independent events?

multiple choice 2
Yes because P(A | B) ≠ P(A).
Yes because P(A ∩ B) ≠ 0.
No because P(A | B) ≠ P(A).
No because P(A ∩ B) ≠ 0.

1 answer

a. The joint probability table is:

B Bc Total
A 0.2 0.12 0.32
Ac 0.5 0.18 0.68
Total 0.7 0.3 1

b. The probability that A occurs is 0.32.

c. The probability that A and B occur is 0.2.

d. Given that B has occurred, the probability that A occurs is 0.2/0.3 = 0.6667.

e. Given that Ac has occurred, the probability that B occurs is 0.12/0.68 ≈ 0.1765.

f. No because P(A∩B) ≠ 0.

g. No because P(A|B) ≠ P(A).