Please select all True statements about Statistical Process Control:

Calculated using customer $($designer$)$ specification and the process STD$.$

Samples statistics $($e$.$g$.,$ average, percentage$)$ are compared to control$-$limits$.$

Applied to verify a process is stable $-$ in$-$control.

Used to find the proportion of individual outputs $($products$)$ that would be accepted by the customer $($designer$)-$ fall within specifications.