Which of the following is not an out-of-control signal for an x-bar chart? 

a. One or more points outside the control limits 

b. Six or more consecutive points moving in the same direction 

c. Fourteen points or more in a row, alternating up and down 

d. Four or less consecutive points that all fall on the same side of the center line

Answer rating: 100% (QA)

c Fourteen points or more in a row alternating up a... View the full answer