[Hussar]

I should have paid more attention in Statistics and Probability in college … but then again, I’m so old … I’d have forgotten by now anyway. :eek:

So here are my problems.

Event A = 8% chance of occurring.
Event B = 67% chance of occurring.

1) What is the probability that at least one (1) of the Events occurs?

2) What happens when the Events depend on each other? For example, in order for Event B to occur, Event A needs to occur first. What are the chances of both events occurring?

Thanks in advance!

Brian

[ebaines]

The prob that at least one event occurs can be calculated in one of two ways. The easy way is to consider that the probability of something happening is 1 minus the probability that it doesn'thappen. In this case, the probability that at least one event occurs is 1 - probability that neither event happens. That would be: 1- (1-.08)*(1-.67), which is 0.6964. The harder way to do this is to add the prob that event A occcurs to the prob that event B occurs and subtract the prob that both A and B occur: 0.08 + 0.67 - 0.08*0.67 = 0.6964.

If A and B are independent events (which I assume they are), and if B depends on A happening also, then the probability that B occurs is simply 0.08*0.67 = .0536.