00:01
So here we have the probability, already given by the question, or having a high quality oil is 0 .35.
00:10
The probability of having a median quality oil in this case is 0 .2.
00:17
And the probability of having no oil is 0 .45.
00:24
So now in letter a, we need to consider what is the probability of finding oil.
00:29
So we want this.
00:30
What is the probability of finding oil? so in this case, here is the same as one minus the probability of not finding.
00:39
So it is the situation that we have no oil.
00:42
So it is 1 minus 0 .45, which is 0 .55.
00:49
Now in letter b here, we need to consider that we have these probabilities here.
00:56
They have a test of the soil.
00:59
And here we are giving that there is like a high quality oil in this soil.
01:04
Here we have 0 .20.
01:08
And here the test.
01:11
And if you have a median quality oil, this will be 0 .80.
01:18
And the test here, when you have no oil, is 0 .2.
01:25
So for the first question, they say the probability of finding oil is good.
01:30
That's true because we have 055.
01:35
So given the probability of finding good soil, so we can have like a high quality or median quality for the type of oils here.
01:45
So in this case, they want to say what is they more likely to find a high quality oil or a median quality oil? or even no quality.
01:57
So basically, you just need to put what is the biggest here.
02:00
So the biggest is the median quality.
02:02
So it is more likely they will find the median quality oil.
02:08
So now let's complete the table that we have.
02:11
So basically we have here, in this case, in this case we have the types of oils here, high quality, median quality, no oil.
02:24
And here we are considering that this is a 1.
02:28
This is 8 .2...