00:01
Hello everyone, so let's do the statistics problem, but before i get started, i recommend that you do the question yourself and come back to see if you got a right or not.
00:11
So hopefully you've done the question yourself and let's working it together.
00:14
So we have that in a poll there is 2 ,100 randomly selected adults.
00:20
So already we have our sample size, which is 210 and in the us and they were asked if they were in favor of the death penalty for a person convicted of murder.
00:32
So we have that out of the sample size, our x value, in this case would be 1701, because it's 1701 of the adults that said that they would be in favor of the death penalty.
00:46
So the first part of this question is asking us to construct our 95 % confidence in the proportion, so that's the keyword here, proportion for all the adults in the united states who are in favor of the death penalty.
00:59
The proportion tells us what kind of like formula we're going to have to end up.
01:03
Using, right? so with 95 % confines of interval, our formula is going to end up talking something like this.
01:12
So p hat plus minus, right, depending on the lower bound or upper bond, the z critical value, which we're going to find using our alpha.
01:26
So we can do our alpha, 1 minus 0 .9, which is 0 .01, or 0 .1, that is our significance.
01:37
And now, the z -critical value, if we want to find that, we have to do our alpha divided by 2.
01:47
That would go to 0 .3 .5.
01:49
If we go to the table, you can find our z -critical value when the level of significance is 0 for 0 .5.
01:55
And then we can multiply this by square root of p hat, applied by q or q is the same thing as 1 minus p hat.
02:08
So i'm just going to put that here, q is equal to 1 minus p hat.
02:13
It's right for sure.
02:16
And then divide that all by n.
02:20
So now we can actually, we can find the z critical value, which we will find is 1 .64...