A manager took samples of size n = 6 hourly from a process for 16 hours and determined the lower and upper control limits for the corresponding x -chart as below: L C L = 65.6224 U C L = 72.5776 Table of Control Chart Constants Calculate the following mean values accurate to 1 decimal place: x = R = Table of Control Chart Constants Sample Size A 2 D 3 D 4 2 1.880 0 3.267 3 1.023 0 2.575 4 0.729 0 2.282 5 0.577 0 2.114 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 11 0.285 0.256 1.744 12 0.266 0.283 1.717 13 0.249 0.307 1.693 14 0.235 0.328 1.672 15 0.223 0.347 1.653 16 0.212 0.363 1.637 17 0.203 0.378 1.622 18 0.194 0.391 1.609 19 0.187 0.404 1.596 20 0.180 0.415 1.585 21 0.173 0.425 1.575 22 0.167 0.435 1.565 23 0.162 0.443 1.557 24 0.157 0.452 1.548 25 0.153 0.459 1.541