The average of allsubgroups becomes the centerline for the lower plotting area. Average of Ranges Example Step 7 - Calculate the upper control limit (UCL) and lower control limit (LCL)for the averages of the subgroups. At this point, your chart will look like aRun Chart. Now, however, the uniqueness of the Control Chart becomes evidentas you calculate the control limits.
Ford Motor Company recommends that the Crown Vic limit its towing to a trailer with a gross vehicle weight of 1500 lbs or less with a tongue weight not to exceed 150 lbs. See HERE.
Additional costs: 1  A pickup to tow the fifth wheel can cost $20,000-$50,000 or more. 2  If the fifth wheel is wider than the tow vehicle, extended side view mirrors are legally required, starting at $4-$50 for a pair that clamp onto the existing side mirrors, or $150-$450 for permanently installed towing mirrors.