00:01
So i'm going to have the d stand for the difference between last year's rating minus this year's rating.
00:08
And you could do it either way.
00:10
But i'm going to do last minus this.
00:11
And you should always not describe to the reader what you're assuming for your variable.
00:18
And so we're going to assume that the mean difference is actually zero, so that there's no change.
00:24
And alternately, that there's a change, meaning we need to do a two -tail test than not equal to.
00:29
So we need to find what our cutoff point is, what our rejection values will be.
00:37
We're assuming that the mean is at zero, and we have 5 % significance level.
00:43
So we want 0 .025 in the upper tail and 0 .025 in the lower tail.
00:49
So in our sample size is 8.
00:53
So for 7 degrees of freedom in that 0 .25 in the upper tail, this t star value, with 7 degrees of freedom corresponds to 2 .365 and this value is negative 2 .365...