The emergency service unit in a hospital has a goal of 3.5 minutes for the waiting time of patients before being treated. A random sample of 20 patients is chosen and the sample average waiting time is found to be 2.3 minutes with a sample standard deviation of 0.5 minutes. Find an appropriate process capability index. Comment on the ability of the emergency service unit to meet the desirable goal, assuming normality. What are some possible actions to consider?