00:01
The following is a solution in number three, and this is where we conduct a hypothesis test.
00:05
I'm going to conduct a five -step hypothesis test using the p -value method, and we're given that a simple random sample of 14 from a normally distributed population, so that's okay for the sample size, has a population standard deviation of 20, a sample mean of 60, and we're testing at the 0 .1 level of significance.
00:24
So since we know what sigma is, and since we're testing for the population, mean mu, since we're given the sample mean, then we're going to use the z test.
00:35
So the z test because we know that population mean.
00:38
So like i said, there are five steps.
00:39
The first step is to state our hypotheses.
00:42
And we are testing, it says, to test whether the mean is less than 70.
00:48
So the null always assumes that there's equality, so mu equals 70.
00:53
And then the alternative, ha, is that mu is less than 70.
00:57
And that's what we're testing.
00:59
We're seeing if it's less than 70.
01:01
Step 2 and step 3, actually, i'm going to work on the calculator because it would take much, much longer.
01:09
But there is a formula you can certainly plug these numbers in.
01:12
But if technology is available, you might as well use it.
01:15
So if you go to stat and then arrow over to test, we're going to do this first thing, the z test.
01:21
So go to 1.
01:22
And we don't have any data.
01:23
We just have summary stats.
01:24
I make sure summary stats is highlighted there.
01:26
And then the mu not, that's the hypothesized value.
01:31
And remember that was 70.
01:32
So that's just your null hypothesis.
01:35
And the rest of this stuff was given to you.
01:37
So the standard deviation of the population was 20.
01:40
The x bar was 60...