$(13-5)$ ?Design specifications require that a key dimension on a product measure $100\backslash$ pm $10$ ?units. A process being considered for producing this product has a standard deviation of $4$ ?units. $-($ a $)$ ?What is process capability here? $-($ b $)$ ?Suppose the process average shifts to $92.$ ?Calculate the new process capability, $-($ c $)$ ?After $($ b $),$ ?what percentage of the items produced will be defective?