00:01
So we have 15 parts are selected, and then we're supposed to assume that the probability of a defect is 0 .05.
00:08
And anytime there are two or more that are defective, then they will stop the process.
00:20
And so on part a, we want to find what's the probability of having it stop, which means that we select 15 and we get l at x stand for the number who are defective.
00:32
And if x is greater than or equal to two, we're going to stop.
00:36
Well, this is following a binomial distribution.
00:39
And so we're going to actually find the complement.
00:42
We're going to find the probability of x being less than two, which means x is equal to zero or one.
00:49
And so this would be equal to that combination of 15, choose none, and have the probability of a defect being 0 .05, and we don't want any of those.
01:01
We want to have all of them be good.
01:05
And then the probability of 15 choose 1, and that 0 .05 to the first power, and the 0 .95 to the 14th power.
01:14
So if you have to show your work out, that's what you'd want to show.
01:17
Now, i'm actually going to hit 1 minus binomial cda and put in 15 and 0 .05 and 1.
01:28
And that will get me my calculations faster because we know that the calculator has been pre -programmed to do this, to know these formulas.
01:36
So it's a great feature.
01:38
When i learned this stuff way back when, we didn't have this feature.
01:43
We had to do it all, crank it all out longhand...