00:01
In this question, we assume that we have five groups of observations named a, b, c, d, and e.
00:07
And we're going to conduct hypothesis tests, t tests, to compare all possible pairs of means.
00:14
So what we want to do here is list the number of pair -wise comparisons that you can do with five groups and then list all the pairs.
00:22
So first thing we'll do is look at our five groups and see that that tells us k equals five.
00:28
And now the number of pairwise comparisons, so the number of pairwise comparisons, first of all, has a nice little formula that we'll use here.
00:41
And our formula is k, which is the number of groups, times k minus one over two.
00:48
So in our case, that would be five times five minus one, which is four, over two.
00:56
And that would be ten.
00:57
5 times 4 divided by 2 is 10.
01:01
And just a note here, this would be the same as using a combination, 5, choose 2.
01:09
So if you're familiar with combinations, you'll see that you would also get 10 if you use that technique.
01:15
Okay, now we want to list out all those pairwise, all those pairs that we have.
01:21
So let's start with a -b, then a -c, a -d, a -e...