00:01
So this problem we are told that we have a shipment of 50, 2 % of which are defective, and so it means p -value is 20 .20 .0.
00:11
Now what this means, 20 % of 50 is 10, so we have 10 defective, and 40 non -defective.
00:20
Now we're going to take a sample of 5, and we pass it if no more than 2 are found defective.
00:28
And we want to find what proportion of these will be accepted.
00:33
And so again, we want no more than two of our sample of five to be defective.
00:39
And so we want the probability that x is less than or equal to two.
00:46
Now let's begin with the probability of zero plus the probability of one plus the probability of two.
00:55
Now the probability of zero, notice that we have 40 that are not defective.
01:05
And if we choose all five of those, that means we'd have zero that are not, the zero that are defective.
01:12
And then this is over 50 choose five because there are 50 total items and we're choosing five of them.
01:20
Now the probability one of them is defective...