in sebastians class, the probability that a randomly selected student has at least one sibling is 0.7. the…

in sebastians class, the probability that a randomly selected student has at least one sibling is 0.7. the probability that a randomly selected student has at least one pet is 0.6. the probability that a randomly selected student has at least one sibling and at least one pet is 0.55. what is the probability that a randomly selected student has at least one sibling or at least one pet? write your answer as a decimal. do not round.
Answer
Explanation:
Step1: Recall the formula for the probability of the union of two events
The formula for (P(A\cup B)) is (P(A)+P(B)-P(A\cap B)), where (A) is the event that a student has at least one sibling and (B) is the event that a student has at least one pet. Let (P(A) = 0.7), (P(B)=0.6) and (P(A\cap B)=0.55).
Step2: Substitute the values into the formula
(P(A\cup B)=0.7 + 0.6-0.55) (P(A\cup B)=1.3 - 0.55) (P(A\cup B)=0.75)
Answer:
0.75