).
For the u-chart, we estimate sigma by calculating the square root of
÷ 
. However, to keep things simple, we have broken this
down into several steps.Now we are ready to begin the calculations for the upper and lower
control limits. As with the other chart types, the control limits
are located at 3 sigma units above and below the mean
().
For the u-chart, we estimate sigma by calculating the square root of
÷ . However, to keep things simple, we have broken this
down into several steps.
The first thing we need to do is to divide by . These two values have
already been entered into the first two boxes below. Complete the
calculation and enter the result in the box outlined in red. Your
answer should be rounded to 7 decimal places.