6. (20 points) The process used to grind certain silicon wafers to the proper thickness is acceptable only if or, the population standard deviation of the thickness of dice cut from the wafers, is at most 0.50 mil. Use to test the null hypothesis 0' = 0.50 against the alternative 6 > 0.50, if the thickness of 15 dice cut from such wafers have a standard deviation of 0.64 mil. Use the 5 step method