00:01
For this problem, to begin, we know that the claim that we're testing is the teacher's hypothesis that the teacher suspects that the average score for her students is greater than the mean score on the standardized test.
00:15
The claim is mu is greater than 100.
00:18
Because that is a statement of strict inequality, that will be our alternative hypothesis, mu greater than 100, and our null hypothesis will be that the mean value is, as claimed, equal to 100.
00:31
We know that we have a sample of size 35, we have a sample mean value, x bar, equal to 103, and a sample standard deviation of 15.
00:43
Now because the population standard deviation is unknown, we'll be doing this using a t distribution, or as a one -tail, right -tail, to be specific, t test.
00:54
Our critical t value, then, will be the t score for n minus 1 degrees of freedom, that's 34 degrees of freedom, and a tail proportion equal to our level of significance, in this case 0 .05.
01:05
Now there are a number of ways to find that critical t value.
01:09
In this case, i'm just going to use my software here...