Vincent,a Quality Control Manager at an Apparel Manufacturing Company,studies and Monitors

Multiple Choice

Vincent,a quality control manager at an apparel manufacturing company,studies and monitors quality using R-charts.He discovers a quality problem with the construction of zippers.Vincent proposes that 25 samples of eight observations each be collected on a daily basis.He plans to prepare an R-chart to monitor the variation in the size of the zippers.The data collected shows that the mean length of the zippers is 15 inches and the average range is 0.5 inches.If D₃ for the R-chart is 0.136,the lower control limit (LCL_R) for the R-chart will be:

A) less than or equal to 1.
B) more than 1 but less than or equal to 2.
C) more than 2 but less than or equal to 3.
D) more than 4.