This question is incomplete, the complete question is;
he Eco Pulse survey from the marketing communications firm Shelton Group asked individuals to indicate things they do that make them feel guilty (Los Angeles Times, August 15, 2012).
Based on the survey results, there is a 0.39 probability that a randomly selected person will feel guilty about wasting food and a 0.27 probability that a randomly selected person will feel guilty about leaving lights on when not in a room.
Moreover, there is a 0.12 probability that a randomly selected person will feel guilty for both of these reasons.
Required:
a. What is the probability that a randomly selected person will feel guilty for either wasting food or leaving lights on when not in a room or both (to 2 decimals)?
b. What is the probability that a randomly selected person will not feel guilty for either of these reasons (to 2 decimals)?
Answer:
a)
the probability that a randomly selected person will feel guilty for either wasting food or leaving lights on when not in a room or both is 0.54
b)
the probability that a randomly selected person will not feel guilty for either of these reasons is 0.46
Step-by-step explanation:
Given the data in the question;
lets A represent person feels guilty about wasting food and B represent leaving the light on when not in room;
probability; feel guilty about wasting food P(A) = 0.39
probability; feel guilty about leaving light on P(B) = 0.27
probability; feel guilty for both P(A ∩ B ) = 0.12
a)
probability that a randomly selected person will feel guilty for either wasting food or leaving lights on when not in a room or both
p( A ∪ B ) = P(A) + P(B) - P(A ∩ B )
we substitute
p( A ∪ B ) = 0.39 + 0.27 - 0.12
p( A ∪ B ) = 0.54
Therefore, the probability that a randomly selected person will feel guilty for either wasting food or leaving lights on when not in a room or both is 0.54
b)
probability that a randomly selected person will not feel guilty for either of these reasons;
p( A ∪ B )' = 1 - p( A ∪ B )
p( A ∪ B )' = 1 - 0.54
p( A ∪ B )' = 0.46
Therefore, the probability that a randomly selected person will not feel guilty for either of these reasons is 0.46
