Which of the following statements about process quality control is NOT true?

Group of answer choices

Assignable cause variation is also referred as special cause variation.

An observation outside the control limits is an example of a special cause of variation.

Common cause variation can be eliminated from the process by removing the potential causes.

The control limits will include $99\mathrm{.}74\%$ of the population under the normal probability distribution assuming that the process is in control.