00:01
We have been given some sample data.
00:03
The sample size n is 250.
00:06
Out of these, 60 of these x -ray machines malfunction.
00:11
We want a confidence interval for the population proportion that malfunction.
00:16
The formula for that is p -hat, point estimate, sample proportion, plus and minus the margin of error, z root p -hat, 1 minus p -hat, over n.
00:28
We have n, we just need p -hat and z.
00:30
P -hat is the proportion of the sample that malfunctions.
00:35
60 out of 250, which is 0 .24.
00:41
Z we get from the level of confidence.
00:44
Initially this is a binomial experiment...