The watson electric company produces incandescent light bulbs. the

     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)