00:01
Hello, welcome to this lesson.
00:03
On this lesson, we'll find 99 % confidence interval for the population mean.
00:13
So that's what we have, sample size of 16, a mean of 21 .58 and a standard deviation of 2 .55.
00:25
Okay, so here we find the confidence interval of the population mean, by getting the lower bound which is the sample standard deviation minus the error then the upper boundary of the sample standard deviation plus the error okay and here the error is equal to the z score for the confidence level times the standard deviation all over the square root of the sample size so here we have, we need to look for the z score.
01:13
We have a confidence level of 99%.
01:19
So if we are looking at an interval, then essentially we are looking at an alpha on 2.
01:28
And here we have an alpha which is the confidence level is 99%.
01:36
Then we have an alpha, which is 0 .01.
01:41
Just 1%.
01:42
And now we are dividing the alpha by 2.
01:45
So we have 0 .005.
01:51
Okay.
01:56
And this would cover essentially 99 .5 the total area under the caf...