00:01
All right, so we want to test whether or not the mean salary of elementary teachers is greater than secondary teachers.
00:09
So we'll set up our null and alternative hypotheses first.
00:13
The null hypothesis is that the means are the same.
00:17
And the alternative is that, in this case i've made mean one and sample one, elementary teachers.
00:26
So our alternative then is that mean one is bigger than mean two.
00:32
So that's the setup.
00:34
Now, what we need to do next is compute the test statistic, which is going to be the difference in the sample means.
00:41
So x bar 1 minus x bar 2 minus mean 1 minus mean 2 over square root of s1 squared over n1 plus s2 squared over n2.
01:02
And that will give us a we're now first we're going to plug values in so x bar 1 is the elementary school teacher so it's going to 48 ,256 and then we're going to subtract the secondary teacher is 45633 now this mean 1 minus mean 2 population since we're assuming that they're equal will always be zero.
01:36
And then we're going to divide that by the standard deviation of sample 1, which is 3912 .4 over sample 1 size, which is 26.
01:49
And sample 2 standard deviation of 5533 squared, divided by its sample size of 24.
01:59
I would do these separately to calculate them just to be careful...