00:01
Suppose we have a population that has a mean of 225 and a variance, sigma squared, of 225.
00:09
And we're going to take various sample sizes, and we're going to calculate the mean and the standard deviation of the sampling distribution of means.
00:20
So for our population, if the variance is 225, that means that the standard deviation is just going to be the square root of 225, which is equal to 15.
00:34
So now for each of these sample sizes, let's say for part a, n equals 9, the mean of our sampling distribution of x bar is just going to equal mu the population mean, and that's 225.
00:49
And this is going to apply to all the other sample sizes as well.
00:53
For the standard deviation of the sampling distribution of x bar, that's going to be the standard deviation of the population divided by the square root of the sample size.
01:05
So in this case, that would be 15 divided by the square root of 9, which is essentially 15 divided by, oh, sorry, 15 divided by 3, which is 5.
01:18
Okay.
01:20
Next one, n equals 49.
01:22
The mean of the sampling distribution of x bar is not going to change.
01:25
That's still mu...