00:01
In this question, we want to find some critical values.
00:03
Part a.
00:04
The alternative hypothesis is that the mean is greater than 10.
00:09
So, first of all, this is a right -tailed test.
00:14
You can tell by the sign.
00:17
If the sign is not equal to, it is a two -tailed test, because you would be interested in a much higher or much lower sample mean.
00:25
If it is greater than, it is right -tailed.
00:28
You only care if you get a very high.
00:30
Sample meet.
00:32
If it is less than, it is left -tailed.
00:34
You only care if you get a very low sample me.
00:37
So that's the tail, one tail specifically right.
00:41
Now we need the critical value.
00:44
So the level of significance is 1%.
00:48
We have told that sigma is unknown and our sample size is 25, which is quite small.
00:54
So with a small sample size and sigma unknown, this is a t test.
00:59
For t, i need to know alpha over 2, which must be 0...