00:01
Consider a process that includes careful testing of each manufacturer defibrillator as an example one.
00:08
Those said below are the numbers of defective defibrillators and successive batches of 10 ,000.
00:13
Construct a control chart for the proportion p of defective defibrillators and determine whether the process is within statistical control.
00:21
All right, so in this case, we know that the sample size is 10 ,000 and that the number of samples is 20.
00:31
So to find the control limits of the chart, we need to find the sum of the defects over the population.
00:46
And so from the list, we have defects of 20, 14, 22, 27, 12, 12, 18, 23, 25, 19, 24, 24, 28, 25, 1719, 1722, 15, 20, which is 400.
01:20
Out of 10 ,000, and there are 20 samples added to 0 .002.
01:41
The control limits for the p chart, then, for the upper control limit, that would be p bar plus three times the square root, of p bar times one minus p bar over the sample size which is 10 ,000 and that's 0 .0033.
02:12
The lower control limit is subtracting we get 0 .0007.
02:21
So now for the p chart we've got our p bar in the middle, our upper control limit at 0 .0033, and our lower control limit at .00007...