An Important Characteristic in the Proper Operation of Ignition Keys

Multiple Choice

An important characteristic in the proper operation of ignition keys for automobiles is the groove width of the key.In a large manufacturing plant that produces thousands of keys,control charts have been established to monitor the process of cutting the groove.It is believed that the measurement (in inches) of the groove width is Normally distributed.Over a period of time,20 samples,each of size n = 5,were selected in order to establish 3-sigma and s charts.From these samples the following were determined: = 0.15932 and
= 0.0193438.Examination of the chart and the s chart for the samples led to the conclusion that the process was in control at this time.What,then,are the estimates of the process mean,,and process standard deviation,?

A)

= 0.00797;

= 0.000967
B)

= 0.00797;

= 0.019344
C)

= 0.15932;

= 0.020578
D)

= 0.15932;

= 0.001029
E)

= 0.00797;

= 0.001029