Answer:
i. Has a liver problems?
= 0.08
ii. Is a heavy drinker ?
= 0.066
iii. If a person is found to be a heavy drinker, what is the probability that this person has liver problem?
= 0.303
iv. If a person is found to have liver problems, what is the probability that this person is a heavy drinker?
= 0.25
v. If a person is found to be a non –drinker, what is the probability that this person has liver problems?
= 0.104
Step-by-step explanation:
We have 2 Events in this question
Event A: People with liver problems
Event B : People without liver problems
Event A: People with liver problems
Let us represent people with liver problems as = (L)
a)8% have liver problems. = P(L)
Under liver problems we have:
b) 25% are heavy drinkers = P( L & H)
c) 35% are social drinkers = P( L & S)
d) 40% are non-drinkers. = P( L & N)
Event B( no liver problem)
Let us represent no liver problem as NL
We are not given in the question but Probability of having no liver problem = 100 - Probability of having liver problem
= 100 - 8% = 92 %
P(NL ) = 92%
From the question, For people without liver problems, we have:
a) 5% are heavy drinkers = P(NL & H)
b) 65% are social drinkers = P( NL & S)
c) 30% do not drink at all = P( NL & N)
An adult is chosen at random, what is the probability that this person
i. Has a liver problems?
P(L) = 8% or 0.08
ii. Is a heavy drinker ?
From the question, we have:
Probability of people that have liver problems and are heavy drinkers P(L & H) = 25% = 0.25
Probability of people that have do not have liver problems and are heavy drinkers P(NL & H) = 5% = 0.05
Probability ( Heavy drinker) =
P(L) × P(L & H) + P(NL) × P(NL & H)
= 0.25 × 0.08 + 0.05 × 0.92
= 0.066
iii. If a person is found to be a heavy drinker, what is the probability that this person has liver problem?
Probability (Heavy drinker and has liver problem) = [P(L) × P(L & H)] ÷ [P(L) × P(L & H)] + [P(NL) × P(NL & H) ]
= [0.25 × 0.08] ÷ [0.25 × 0.08] + [0.05 × 0.92]
= 0.303030303
Approximately = 0.303
iv. If a person is found to have liver problems, what is the probability that this person is a heavy drinker?
P(L & H) = 25% = 0.25
v. If a person is found to be a non –drinker, what is the probability that this person has liver problems.?
People with liver problems are non-drinkers. = P( L & N) = 40% = 0.4
People without liver problems and do not drink at all = P( NL & N) = 30% = 0.3
Probability (non drinker and has liver problem) = [P( L & N) × P(L & H)] ÷ [P( L & N) × P(L & H)] + [ P( NL & N) × P(NL & H) ]
= [0.4× 0.08] ÷ [0.4 × 0.08] + [0.3 × 0.92]
= 0.1038961039
Approximately ≈ 0.104
