00:01
We have been given some sample data.
00:02
The sample size n is 80.
00:05
Out of these, 62 people answered yes.
00:10
And we want to use this to make a confidence interval for the population proportion.
00:15
So the formula we need is p hat, sample proportion, point estimate, plus and minus the margin of error, z root, p hat, 1 minus p hat, over n.
00:28
So we need p hat.
00:29
This will be our point estimate.
00:31
And that's the proportion of our sample who said yes.
00:35
62 out of 80, which is 0 .775.
00:42
So there's the point estimate.
00:44
We also need z.
00:46
We get that from the level of confidence.
00:49
Right now, this is a binomial experiment.
00:52
N independent trials, two outcomes, yes or no...