Random samples of four items are selected from a manufacturing process at regular intervals and a certain quality characteristic is measured. After 25 samples, ΣX = 15,350 and ΣR = 411.4. To construct a range chart, what is the lower control limit (LCL) for the range?
A) 602.004
B) 411.400
C) 625.666
D) 0.00

Question

Quizplus · Accepted Answer

The lower control limit (LCL) for a range chart is calculated as LCL = D3 * R̄. For a sample size of 4, D3 is 0. Since D3 is 0, the LCL is 0.00.

Random Samples of Four Items Are Selected from a Manufacturing