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.
They have charts that tell them what class of hitch you can safely put on what vehicles, and somehow I doubt you could get anything but the smallest class hitch for it. That would be sufficient to pull a 5x8 trailer but not much more than that. At U-Haul, a hitch for the Ram fully installed would probably run $170-$200.For the T-Bird, more like $125-$150. As for the weight and cost of the trailer, sorry but that I can't advise you on-it's been a while.hat would be sufficient to pull a 5x8 trailer but not much more than that. At U-Haul, a hitch for the Ram fully installed would probably run $170-$200. For the T-Bird, more like $125-$150.