00:01
So we're looking at visits to a car dealer.
00:04
And we're going to be drawing a venn diagram, as it recommends.
00:08
So we've got second -hand cars and japanese cars.
00:13
Of course, you can have both.
00:18
If these are actually independent, we will find out soon enough.
00:22
Hypothetically, you should be able to get a second -hand japanese car.
00:26
We're going to see if that's actually happening here.
00:29
So the probability, but you get neither, so buying no car at all, buying some other type of car is 55%.
00:37
So that's outside of the diagram.
00:40
It's, let's say this circle here is the japanese cars, and this circle here is the second -hand cars.
00:49
Okay, 25 % by second -hand, 30 % by japanese cars.
00:55
So this entire circle, including this bit in here, is 30%.
01:01
This entire circle here is 25%.
01:06
Are they independent? they cannot be.
01:09
Because if we add up all of these probabilities, we get over 100%.
01:12
There has to be some overlap here.
01:16
So, what is the probability that they buy a second hand and japanese car? well, we've got 55 % here.
01:26
We should really only have 45%.
01:28
So we do have some overlap.
01:31
So if we put in 10 here, that would make this 20 and this 15...