Find the control limits for the R-chart with = 7 and sample size of 7.
A)LCL = 2.622 and UCL = 66.378
B)LCL = 0 and UCL = 14.028
C)LCL = 0.532 and UCL = 13.468
D)LCL = 27.5 and UCL = 41.5

Question

Find the control limits for the R-chart with  = 7 and sample size of 7.
A)LCL = 2.622 and UCL = 66.378 
B)LCL = 0 and UCL = 14.028 
C)LCL = 0.532 and UCL = 13.468 
D)LCL = 27.5 and UCL = 41.5

Quizplus · Accepted Answer

The control limits for the R-chart can be calculated using the formula LCL = D3*R and UCL = D4*R, where D3 and D4 are constants from a table based on the sample size and R is the average range of the samples. For a sample size of 7, D3 = 0 and D4 = 2.574. Therefore, LCL = 0.532*R and UCL = 13.468*R. Using the given value of 7 for R, we get LCL = 2.622 and UCL = 66.378, which corresponds to option C.

Find the Control Limits for the R-Chart with =