00:01
Hey there, welcome to numerate.
00:02
We have an economist trying to determine if this evidence that the average family income in a specific community is more than $80 ,000.
00:12
So should we use what kind of hypothesis test? two -tail, upper -tail, or lower -tail.
00:18
So let's define each.
00:19
Okay, so let's do two -tail first.
00:24
Two -tail.
00:26
So a two -tail test is where the null hypothesis, let's do this, no hypothesis, where the mean.
00:36
Is equal to zero or in this case it will be in this case it will be equals to 80 ,000 okay alternative hypothesis would be that's not equal to 80 ,000 so you can see already this is not our case because we're looking for more than and then let's do right tail so for our right tail we'll have our no hypothesis where the average is actually less than 80 ,000 and our alternative hypothesis will be the average is greater than 80 ,000 right so this will be a right tail or it can be like this and then now finally our left tail our no hypothesis will be the opposite to the right it will be the average is greater than equal to 80 ,000 and our alternative hypothesis would be the average is less than 80 ,000.
02:06
Okay, in this case, we're trying to test if the average income is more than 80 ,000, and whenever you see a statement, that should be connected to the alternative hypothesis, okay? so let's do our actual one, no hypothesis, and our alternative hypothesis.
02:28
Okay, yep, and then from there, so we're going to work on our alternative first, so it's more than 80 ,000.
02:35
So the mean is more than 80 ,000.
02:41
Okay.
02:42
And then our normal hypothesis will be the opposite...