00:01
In this problem, they are testing the difference in temperatures between two years, were the same places.
00:06
And they asked us, the first question they asked in a, let's put here, a, is it starts right here, what type of test is appropriate.
00:20
So what type of test is appropriate for this? so in this case, because we're doing the same place and we're doing, we're computing the difference, this won't be a matched pair test so a two sample matched paired or two sample matched pair test because we're testing the same two places at two different times and that will be the one that is appropriate for this situation in b they want us to state the hypothesis so you always want to start with the null the alternate but the first one you want to do always is the alternate so the alternate should be the claim or what we're trying to test so they want to find out whether the temperatures have increased have increased so because they want to know if the temperatures have been increased and we already have the difference our hypothesis will be that the difference is greater the difference between the the later year minus the the first year the the first data so it's greater than zero and our no hypothesis then will be that it's equal to zero.
01:39
In some places, some books and some schools, they like to put it mathematically strict like this, less or equal than.
01:46
But in many books and i myself like to put it this way because this is more in the spirit of what we're trying to test, whether it has increased or not or has stayed the same.
01:57
So then they want to find the standard error of the mean of the difference...