00:01
Okay, so here we do a two proportion z test where our null hypothesis, h -0 is that p -1 is equal to p -2, and then our alternative hypothesis is that p -1 is not equal to p -2.
00:11
So that's part a, according to our sample, the first sample proportion, p -1 -hat, is going to be 648 divided by 1 ,011.
00:19
That's going to be equal to 0 .64, say, 095 .95.
00:25
And then for p -2 hat, 720 divided by 1 ,200, is going to be equal to 0 .6.
00:33
So now we see that the first sample has a high proportion for supporting same -sex marriage.
00:40
And then for part b, we have that the proportion p -hat is going to be equal to 648 plus 720, so that's 1 ,368 divided by 1 ,11 plus 1 ,200, so divided by 2211 is going to be equal to 0 .6187.
01:00
And then we get that our standard error is going to be equal to the square root of p hat times one minus p hat times one over n1 plus one over n2 under the square root.
01:20
And we see that the standard error is going to be equal to 0 .0274...