So we're giving a chart for data over a 12 year period. We know things that happened in the Northern Hemisphere and the Southern Hemisphere, and then they categorize the storms as tropical depressions, tropical storms or hurricanes. And so we have this data and we're not using all of it, But just quick, jot it down. So we have our reference and I added up this column, by the way, and typically I do that when I'm given data, they're called the marginal Frequencies and just add up those columns on get some totals. And, uh, this total happened to be this.
And then, um, I didn't happen to add up all of these because I didn't need all that some. But I happen to add up these two to show how many hurricanes they were. Now we want to find, and you have to be careful about the way the questions worded we want to find. And they said in the question they said something about determining what the probability waas for having If you were in the Northern Hemisphere, what's the likelihood of a hurricane happening? And they didn't order it exactly that way. But that's really what was meant by that title.
So if the, uh, you're looking at the weather pattern for unearth the Northern Hemisphere what? How likely was that storm to have been a hurricane? And so we look at how many people we don't care about the Southern Hemisphere. We only care about this 821 storm patterns over that 12 years. And how many of those were equivalent were, Ah, Hurricane. And that is 379. So the wording of the question again was a conditional.
We don't we're not looking at all. The hurricanes were on Lee looking at this column theme Northern Hemisphere and how many of those in the Northern Hemisphere actually were hurricanes? And so if I click that my calculator 3 79 divided by 8. 21 I get a about 0.462 Okay, 0.46 to which we could call 46.2%. And that answers find that answer is fine. As long as this is a reduced fraction.
That answer is also fine, but typically we give a decimal percent. So that was for a and then for B. When we look at B. They're talking about hurricanes in general. And if ah hurricane occurred, how likely was it to have happened in the Southern Hemisphere? So now we only care about looking at hurricanes.
We only care about looking at the hurricane pattern. And we had 904 in that 12 year period. And how many of those occurred in the Southern Hemisphere? Will 525 did okay, out off a total of 904. And so when we divide that by 25 divided by 904 we get about 9040.581 which we can also call 58.1%. So, more typically, we would give one of these two answers unless they specifically say a decimal or percent.
So be careful about the reading of the question. Look and see if there's a condition that must have taken place first and then in a table like this, you'll either be using only a column, as we did in this first problem or in the second problem, we're Onley using that one row. Okay,.