00:01
All right, so we want to determine whether or not the majority of people who celebrate christmas wait until christmas date open their presence.
00:09
And based on a telephone poll, we have some data here.
00:12
So the first thing wants to do is determine the sample proportion.
00:15
That's going to be our p hat.
00:17
And that's just x divided by n in our sample.
00:20
X being the number of people who wait till christmas day, so that's 442, divided by the total number of people in the sample, 850.
00:29
Generally, we like these as decimals if we can.
00:34
And that gives us a decimal of 0 .5 .2.
00:39
So that's our p hat.
00:41
Now, we want to test that the 1 % significance do the majority of people more than 50 % open on christmas day.
00:49
So let's set up our null and alternative hypotheses.
00:53
And the null is that the 50 % or less open on christmas day.
01:00
And the alternative is that more than 50 % open on christmas day.
01:09
And there's a couple ways we can do this, a p -value approach, a test statistic approach.
01:16
We can do this with a p -value.
01:18
So first we have to compute the z score, and the z score is given by the proportion statistic minus the population value divided by square root of the population value, one minus the population, value over the sample size...