00:01
In question 19, we're asked to give the power of the test.
00:04
So we have a sample of water is being tested for ecoli, and we're told that the null hypothesis is that the sample does not contain ecoli.
00:14
And then we're also given two statements.
00:16
So the first statement is the probability the sample does not contain ecoli, but the tester thinks it does is 0 .012.
00:24
So if we analyze the statement, we can see that this part, the sample does not contain ecoli, is basically just another way of saying that the null hypothesis is true.
00:40
And in the second half of the sentence, the tester thinks it does, is another way of saying that the no hypothesis is rejected.
00:54
And so this is a situation of a type 1 error.
00:57
Basically, the no hypothesis is rejected, yet it is true.
01:03
And the probability of a type 1 error is alpha.
01:07
So that doesn't help us get to our answer, which is we want to provide the power of the test...