00:01
For each of the situations described here, we are asked to come up with the null and alternative hypotheses for a significance test about the population mean.
00:16
For the first one, apartments are advertised to be 1 ,250 square feet, but some tenant group thinks that the apartments are actually smaller than advertised.
00:30
Conventionally, the null hypothesis is that there is no difference between what was originally claimed and what the real situation is.
00:40
So in this case, the null hypothesis can be that the mean is at least the 1 ,250 square feet that were claimed.
01:01
And the alternative hypothesis be that the mean is actually less than 1 ,250.
01:10
Now, obviously, the notation that we're using here is h -sub -not is the null hypothesis, and h -sub -a is the alternative hypothesis.
01:35
For the second scenario, we have larry's car, which averages 32 miles per gallon on the highway.
01:40
He switches to a new motor oil that is advertised to increase gas mileage.
01:46
So after driving 3 ,000 highway miles, he wants to determine if his gas mileage has actually increased.
01:55
Here the null hypothesis is that there is no improvement.
02:02
So that is the mean is no more than 32 miles per gallon.
02:12
And the alternative hypothesis is that the mean is greater than 32 miles per gallon...