00:01
So we're given our population size of 10 ,158, and our sample size is 160, and our x, oops, our x value, the number of successes is 40, and we want to find a 95 % confidence interval for the population proportion.
00:21
And so this is part a.
00:23
And our problem is that if i take 5 % of this, the sample size is too large.
00:28
So we have to use that correction factor.
00:32
So we're going to take what we got, which is the 40 out of 160, plus or minus, and since we want 95%, that will be that 1 .96, and i'm sure you have memorized.
00:43
And then we'll have that little correction.
00:46
I'm going to might show it a little bit differently than what they show.
00:48
This is 1.
00:49
This is 0 .25.
00:50
So we have 0 .25 times 0 .75.
00:54
And typically we divide by n, but we're going to divide by n minus 1.
00:58
And then it's times that correction factor...