Property
Find probabilities of compound events using organized lists, tables, tree diagrams, and simulation. Understand that, just as with simple events, the probability of a compound event is the fraction of outcomes in the sample space for which the compound event occurs.
A compound event is an event that can be viewed as two or more simpler events happening. If the simple events do not influence each other, they are called independent events. For independent events, the probability of the compound event is the product of the probabilities of the simple events.
Examples
- The probability of rolling a 4 on a die (61) and flipping heads on a coin (21) is 61×21=121.
- A bag has 3 red and 2 blue marbles. The probability of drawing a red marble, replacing it, and then drawing a blue marble is 53×52=256.
- A weather forecast gives a 20% chance of rain on Saturday and a 50% chance on Sunday. The probability of rain on both days is 0.20×0.50=0.10, or 10%.
Explanation
A compound event combines two or more simple events. If they are independent (one does not affect the other), find the total probability by multiplying their individual probabilities. It is like a chain reaction of chances!