00:01
They're looking at whether the garlic is going to make the ldl get lower.
00:07
And so we have a sample size of 47, and we have the before level of the cholesterol minus the after level of the cholesterol after taking these, the garlic.
00:18
And we find that the mean change is to drop 2 .9 units with a sample standard deviation of 18 .5.
00:28
And our task is to find a 99 % confidence interval for the true mean difference.
00:36
And so we need to take our 2 .9.
00:41
And we need to, i had to use my inverse t to find what appropriate test t value to use.
00:50
I want to have 99 % in here, which means we're going to have 0 .005 down here and 0 .005 up here.
00:58
And i know my degrees of freedom is 46.
01:01
So i want the t value that has 0 .005 in the upper tail or 0 .005 in the lower tail that has 46 degrees of freedom.
01:12
And so i used my software to find out that this is negative 2 .687, and this one is positive 2 .687.
01:21
And so our confidence interval will be that 2 .867, 2 .687, 2 .687.
01:28
I should say.
01:30
I wrote it, right? i'm saying it wrong.
01:32
And then times our sample standard deviation divided by the square root of 47...