00:01
We have been given some sample data.
00:02
Sample size n is 540.
00:05
Out of these, 76 experienced an interruption in their high -speed internet service in the previous month.
00:12
We want a point estimate for the population proportion and then a confidence interval.
00:17
I will start by drawing the formula for the confidence interval.
00:21
It's p -hat, sample proportion, point estimate, plus and minus the margin of error, z root p -hat, 1 minus p -hat, over n.
00:32
So part a, we want this sample proportion, proportion of the sample that meets the criteria.
00:38
76 out of 540, which is 0 .1407, two four decimal places.
00:48
So you've got that one correct.
00:52
Now for making the interval, we need z.
00:54
We get z from the level of confidence.
00:57
Initially this is a binomial experiment.
00:59
N independent trials, two outcomes, they experienced an outage or they didn't...