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Hi, i'm david and i'm here to help you answer your question.
00:03
Now let me bring up your question here.
00:06
In the question here we are going to discuss about the hypothesis testing.
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Here i want to test the claim that on the machine fan plate must be replaced if the proportion standard deviation it will be not exist by the sigma square equal to the 018.
00:25
It means then want to test the known hypothesis that the sigma square small equal to the 0 .118 versus the alternative hypothesis than the sigma square greater than the japan 18.
00:41
Notice that this will be a rite -tel test.
00:45
We're given the sample size n equal to 81 and the s square that will be the sample variance equal to the 027.
00:55
And from this information, the first time we need to find the test statistics, denoted by the square the formula will be the n minus 1 time when the sigma square time with the n square divided by the sigma square and if we're looking the value we have the 81 minus 1 time when the 0 .27 square divided by 0 .1 1 a square if we compute 0 .27 devalu 8 square the answer times 80 then we get equal to the 180 now the next step we will need to find the level of the significance.
01:36
So the level of the significance, it will equal to the n -far, and this one equal to the 0 -0 -1.
01:49
And then the next time we need to find the degree -vidum, degree -vidum equal to n -1 and equal to the 81, minus 1, and equal to the 80.
01:57
And then we need to find the 90 % confidence interval on the population standard deviation.
02:02
So we have the 90 % confident interval for the sigma.
02:11
The formula will be the sigma, it will be between the n minus 1, 10 times with the n square over the k square on the right, 10 minus 1, 10m, 10 ,000, 10 divided by the k square on the left...