00:01
So we want to find what the p value is for determining whether there's a difference between these two.
00:07
So again, we would be assuming that the two proportions are equal and alternately that the two proportions are different.
00:18
And so we have the z value would end up being that difference between the two proportions divided by the square root of that .45.
00:32
I'm sorry, that would end up being the pooled p.
00:34
The pooled p would end up being the 45 plus 40 out of 200.
00:43
And that will be, that's the pooled p.
00:46
And let me quick erase that.
00:49
And so then you would end up having the pooled p, 1 minus that pooled p, 85 over 200 and 1 minus 85 over 200.
00:58
And then 1 over the first sample size plus 1 over the second sample size.
01:02
And we can also enter that in as a two proportion z test and having the 45 out of 100 and then the 40 out of 100 and doing a not equal to.
01:17
And the test statistic, the z value for this test is .7152 and the p value for this test is .4744.
01:29
So we would fail to reject null.
01:32
Fail to reject the null.
01:35
And there is our p value.
01:38
Now part b says increase the sample size to 400 and let's see what happens.
01:44
And increase the sample sizes.
01:47
So now each sample size and 1 and n2 will be 400.
01:52
And i'm going to change my two proportion z test to show that those sample sizes are changing.
02:00
And two proportion z test.
02:02
So now we're going to have the 45, the .45.
02:07
When we put that here, we're going to change the sample sizes basically to the 400.
02:15
And let me quick do that for you...