Final answer:
To find the probability of the union of two events A and B, you can use the formula P(A OR B) = P(A) + P(B) - P(A AND B), where P(A AND B) is the probability that both events A and B occur simultaneously.
Step-by-step explanation:
To find the probability of the union of two events A and B, you first need to find the probabilities of each event individually. Let's say the probability of the event 'student has a sibling' is P(A) and the probability of the event 'student lives with a single parent' is P(B). To find P(A OR B) (the probability of the union of the two events), you can use the formula P(A OR B) = P(A) + P(B) - P(A AND B), where P(A AND B) is the probability that both events A and B occur simultaneously.
For example, if P(A) = 0.4 and P(B) = 0.3, and the probability of both events happening together is P(A AND B) = 0.2, you can calculate P(A OR B) as follows: P(A OR B) = P(A) + P(B) - P(A AND B) = 0.4 + 0.3 - 0.2 = 0.5.