Question: XYZ produces bearings for bicycle wheels and monitors the process with an X‾ ­ chart for the diameter of the bearings. The X‾ ­ chart is based on subgroups of size 4. The target value is 0.37 inch, and the upper and lower limits are 0.35 and 0.39 inch, respectively (assume that these are based on three-sigma limits). Wheeler, which purchases the bearings from XYZ to construct the wheels, requires tolerances of 0.39 ± 0.035 inch. Oversized bearings are ground down and undersized bearings are scrapped. What proportion of the bearings does Wheeler have to grind and what proportion must it scrap? Can you suggest what Wheeler should do to reduce the proportion of bearings that it must scrap?