Answer true or false. (NOTE: A statement that is not always true should be deemed false, so consider the statements carefully.) For each false statement, provide a corrected version of the statement.

a. The upper control limit for monitoring a continuous variable describing the quality of a manufacturing process is customarily set equal to the variables mean plus three standard deviations of the variable.

b. If the upper control limit is known for a c-chart used to monitor a countable process parameter, then with no other information the mean value of the parameter when the process is in statistical control can be deduced.

c. Without process specification limits, six-sigma analysis of process capability and process performance cannot be done.

d. If the process capability index is less than one, then significant scrap is being generated. The only possible solutions to this problem are (1) reduce process variation, or (2) re-define the product and process so that wider specification limits would comprise acceptable quality to the customer.