00:01
All right, so we're looking at some data here.
00:02
There are three methods of production, a, b, and c.
00:05
And what we're looking at within each of the three methods are six batches of 10 ,000 components.
00:13
And these are the faulty parts that are constructed, or that are produced within those batches.
00:20
And so we want to know if there's a significant difference between the methods.
00:26
So our null hypothesis will be that the means are all equal.
00:30
Mu one is equal to mu two is equal to mu three.
00:32
And i wrote a one instead of a two, sorry about that.
00:37
The alternative hypothesis is that the means are not all equal.
00:48
All right, and so we're gonna run a one -way anova on this.
00:52
And so we have the, i went ahead and calculated the sample sizes of each, so six, the sums, you add all of them up.
01:00
The means, you take the sums of the sample size.
01:03
And 159, 142, 134, those are the sample means.
01:06
And we want to see are they all equal.
01:10
And we have the variances here.
01:12
And the variance, i use the var .s function and put in your data, and then that's in the spreadsheet.
01:20
And those are the variances, square root of that, number is the same deviations.
01:24
So we can see those statistics here based on those samples.
01:29
And the grand mean is 145.
01:33
You take the grand mean of all the data here.
01:36
There are three groups, k is three.
01:38
Big n, the total observation count is 18, six times three.
01:44
We're gonna use this information to fill in our anova table.
01:48
And we should say that we're gonna test this significant, this hypothesis at the alpha 0 .01 level of significance, which means if our p -value falls less than this alpha, we're gonna reject the hypothesis.
02:01
So to fill in this table, we want the p -value.
02:05
To get the p -value, we need the f statistic.
02:07
That's the mean square of the treatments divided by the tr, divided by the mean square of the error.
02:15
The mean squares of the treatment and the error are found by taking their corresponding sum of squares divided by the degrees of freedom.
02:21
So this is where our calculations lie.
02:24
Degrees of freedom treatment, degrees of freedom is k minus one, k is three, so this is gonna be two.
02:38
And the error, the degrees of freedom is n minus k, so 18 minus three is gonna be 15.
02:45
And then the total degrees of freedom is big n minus one, so 17.
02:51
Just gotta clean up our workspace here.
02:55
Great, now we need our sum of squares...