00:01
Once again, welcome to a new problem.
00:06
This time we're dealing with hypothesis testing.
00:10
We're dealing with hypothesis testing.
00:15
And of course, when it comes to hypothesis testing, we could always think about an independent samples t -test.
00:27
So we can think about independent samples t -test.
00:31
And whenever you see an independent samples t test, you're assuming two independent samples, and you want to compare the differences between these two samples.
00:44
The test statistic for the independent samples t test is the same as t equals to x by 1 minus x by 2, mu 1 minus mu 2.
00:59
And this is the hypothesized population mean difference.
01:12
So the hypothesized population mean difference.
01:15
And it's hypothesized that the difference is going to be zero.
01:19
And then you divide by the standard error.
01:23
Since the variances of the two groups assume not to be equal, then the standard error will have this format.
01:34
So this is the standard error for an equal variances.
01:45
So the standard error for an equal variances.
01:50
We're looking at this problem, we're looking at a new problem and in this particular problem, we have specific requirements.
01:58
Think about the iq for history versus psych majors and we select 16 students, psych students, we have eight psych students and eight history students.
02:17
And the researcher is interested in the investigation of the difference in iq scores between the two groups of students.
02:26
So we want to test the hypothesis at alpha equals 2.
02:31
There are certain specific requirements that we want to run so we want to determine if there's a difference in iq scores between psych and history majors so in part a they're asking to determine the appropriate test so we're going to say the most appropriate test the most appropriate test, the most appropriate test is the independent samples t test.
03:14
So that's their most appropriate test for this particular problem, the independent samples t test.
03:20
The next requirement is that we want to get the now and alternative hypothesis for this problem.
03:29
So the now hypothesis, we are hypothesizing that the two populations of history and psych majors have similar or the same iq scores.
03:39
And then the alternative hypothesis, we're hypothesizing that there's a difference in the iq scores between these two tests.
03:49
So it's a two -tail test.
03:51
We want to get the critical values for this test.
03:54
It's a two -tail test, meaning that that the critical values on both sides, this is positive t alpha over 2 and negative t alpha over 2.
04:07
Remember the degrees of freedom...