The Watson Electric Company produces incandescent light bulbs. The following data on the number of lumens ...

     Problem 1. The Watson   Electric Company produces incandescent light bulbs. The following data on the number of lumens   for 40-watt light bulbs were collected when the process was in control.          Sample 1 2 3 4          1 614 602 598 600   2 597 601 590 606   3 581 603 585 599   4 620 605 595 588   5 595 609 608 604   

      a) (15   points) Calculate the control limits for an R-chart.    b) (15 points) Calculate the control limits for   an    x-bar -chart.      c) (10 points) Since these data were collected, some   new employees were hired. A new sample   obtained the following readings: 575,   603, 623 and 583. Is the process still   in control? (hint: use the original sample set as a benchmark to assess the   new sample)