00:01
So we have 7 % have a fear of spiders.
00:03
That means 93 % do not have a fear of spiders.
00:08
So we're going to look at 10 people, and we want to know the following probabilities.
00:12
I'm going to start with this one exactly 2.
00:15
So we don't know which 2 of the 10 have that fear of spiders.
00:19
So we're going to take a combination of 10 picking 2 at a time to see how many groups of 2 we can get.
00:25
Now those 2 are going to be afraid of spiders.
00:28
So their percentage is 0 .07.
00:31
The other 8 will not have a fear of spider, so that would be 0 .93.
00:35
So i'm going to have that's going to be my probability.
00:39
Now we're going to say at least 1.
00:42
Well, if at least 1, that means we have anywhere from 1 to 10.
00:47
So the number that's not included in there is 0.
00:51
So if we find the probability of 0, then we can say, subtract that from 1, and we would have everything else from 1 to 10.
01:01
So let's do that.
01:02
Probability of 0 having a fear of spiders.
01:05
That means all 10 do not have a fear.
01:09
So we would say that's 0 .93 to the 10th power.
01:14
Now we want to know if we're at most 1.
01:17
That would mean we take the probability of 0 and then we're going to have the probability of 1.
01:23
Well, we've already got the probability of 0 in this expression here...