WHAT_IS_THE_CENTER_LINE_VALUE_FOR_THE_AVERAGE_NUMBER_OF_EVENTS_CONTROL_CHART,_WHEN_THERE_IS_NO_STANDARD_GIVEN??$

WHAT_IS_THE_CENTER_LINE_VALUE_FOR_THE_AVERAGE_NUMBER_OF_EVENTS_CONTROL

1.	WHAT_IS_THE_CENTER_LINE_VALUE_FOR_THE_AVERAGE_NUMBER_OF_EVENTS_CONTROL_CHART,_WHEN_THERE_IS_NO_STANDARD_GIVEN??$
A.	<span style="text-decoration:overline;">t</span>/n
B.	<span style="text-decoration:overline;">2t</span>/3n
C.	2 <span style="text-decoration:overline;">t</span>/n
D.	<span style="text-decoration:overline;">t</span>/2n
Answer» B. <span style="text-decoration:overline;">2t</span>/3n