PROBABILTY OF UNION OF EVENTS

Which of the following is the following illustrates the probability of union of two events A and B?

• P(A ∩ B) = P(A) · P(B)

• P(A ∩ B) = P(A) · P(B) ÷P (A ∩ B)

1The General Addition Rule is used to determine the probability of either event A or event B occurring and states 𝑃(𝐴 𝑜𝑟 𝐵) = 𝑃(𝐴) + 𝑃(𝐵) – 𝑃(𝐴 𝑎𝑛𝑑 𝐵). Why is 𝑃(𝐴 𝑎𝑛𝑑 𝐵) subtracted?

• You do not have to subtract P(A and B) if A and B are statistically independent.

• This rule determines the probability of event A or B occurring, not A and B, so this factor is subtracted.

• There is no explanation other than it’s just a part of the theory.

• P(A and B) has been counted twice through P(A) and P(B).

From numbers 1 to 8. What is the probability of choosing an even number or a number less than 4?

Out of 735 residents surveyed in a certain community, 426 like watching basketball, 132 like watching volleyball, and 114 like watching basketball and volleyball. What is the probability that a randomly selected residents like watching basketball or volleyball?

The table below provides information about the students in an accounting class:

If a student is selected at random from the class, what is the probability that the student is a male or a senior?

• 0.882       

• 0.588       

• 0.471          

• 0.745