00:01
All right, so we are testing a claim that the mean of a population is greater than 1270.
00:06
And so the null hypothesis is that the mean would be less than or equal to 1270.
00:12
And we have the sample mean x -bar is 1287 .06.
00:16
The standard deviation of the population sigma is, let me try that again with, so it looks a little more official.
00:26
There we go, 205 .23.
00:27
That's our standard deviation of the population.
00:29
The sample size was 300.
00:31
And we're told the distribution about the population is normal.
00:34
And that said, the distribution about the sample mean will also be normal.
00:39
And so we're going to figure out if we can accept or reject the null hypothesis.
00:45
And we should state that we're testing this at the alpha of 0 .05.
00:48
So it's a one -tailed test.
00:50
We're looking strictly greater than, so it's one -tailed test.
00:55
And here's the mean.
00:57
And the mean of the distribution about the sample mean is the same as that of the population.
01:03
And here's the x -bar, 1287 .06...