4. A duality.r assurance manager is assessing the capability of a process that puts pressurized grease in an aerosol can. The design specifications call for an average of ED pounds per square inch {psi} of pressure in each can with an uppertolerance limit of 65 psi and a lower tolerance limit of 55 psi. It is known that cans have an average of ED psi. If the qualityr assurance manager wants to ensure that the fraction of cans that do not meet the specifications is as low as 2x109, what should he the standard deviation of the process