00:01
For this exercise, we have a lower one -tailed hypothesis test with the chosen level of significance of 0 .1, a true mean of 42, and a sample size of 15, and a test statistic, a t -test statistic of minus 1 .42.
00:18
And we are asked for the observed level of significance from this test.
00:24
Another way of asking that is what is the p -value associated with this test.
00:28
And this comes directly from our calculated test statistic of minus 1 .42.
00:35
So if this is the t distribution at n minus 1 or 14 degrees of freedom, our test statistic came out to about here.
00:49
Now since this is a lower tailed test, the p value is equal to the probability of having gotten a test statistic less than the one that we got.
01:07
This is equal to the area under the curve and to the left of our test statistic.
01:12
Statistic.
01:22
Again, this is the area just in the lower tail because this is a lower tail to test.
01:29
So let's use software to solve this probability or this p -value.
01:33
So in excel, we can use the t -distribution function...