00:01
So for each of these, we're going to start by writing out the two opposite statements, and then we're going to identify which one is the null hypothesis and which one is the alternative hypothesis.
00:10
So for the first one, we have the mean age is less than 16 years.
00:16
So our two possible statements are going to be less than 16, and the opposite of that is greater than or equal to 16.
00:25
Now, remember that our null hypothesis is always the one that contains the equal sign with it.
00:30
So that tells us that this one is our null hypothesis, and this one is our alternative hypothesis.
00:38
For b, we have the mean height is greater than 6 foot 6.
00:44
So one possibility is mu is greater than 6 foot 6, and the opposite of that statement is less than or equal to 6 foot 6.
00:59
So we look for the one that has the equal sign in it, and that one's our null hypothesis.
01:06
And that tells us our other one is our alternative hypothesis.
01:11
For c, we have the mean elevation drop is at least 285 feet.
01:17
Saying at least is the same thing as saying greater than or equal to.
01:23
And the number we had was 285...