Factors for Calculating Three-Sigma Limits for the Chart and R-Chart Factor for UCL Factor for Factor for Size of and LCL for LCL for UCL for Sample x-bar-Charts R-Charts R-Charts (12) A2 D3 D4 2 1.880 0 3.267 3 1.023 0 2.575 4 0.729 0 2.282 15 0.577 0 2.115 6 0.483 0 2.004 7 0.419 0.076 1.924 8 0.373 0.136 1.864 9 0.337 0.184 1.816 10 0.308 0.223 1.777 Source: 1950 ASTM Manual on Quality Control of Materials, copyright American Society for Testing Materials. Reprinted with permission. Construct a 3-sigma R-chart for the length in centimeters of a part from the following table. What is the upper control limit of your R-chart? Sample #Observation 1 Observation 2 Observation 3 Observation 4 1 0.486 0.499 0.493 0.511 2 0.499 0.506 0.516 0.494 3 0.496 0.5 0.515 0.488 4 0.495 0.506 0.483 0.487 0.472 0.502 0.526 0.469 0.473 0.495 0.507 0.493 0.495 0.512 0.49 0.471 0.525 0.501 0.498 0.474 0.497 0.501 0.517 0.506 0.495 0.505 0.516 0.511 5 6 7 8 9 10 OA) 0.51 B) 0.73 C) 2.28 OD) .032