Problem 1 OM 306

a) An inspector found an average of 3.9 scratches in theexterior paint of each of the automobiles being prepared for shipment to dealers.

Calculate three-sigma control limits (UCL and LCL) for this case using a c chart

b) Before shipping lawn mowers to dealers, an inspector attempts to start each mower and notes any that do not starton the first try. The lot size is 100 mowers, and an average of four did not start.

Calculate three-sigma control limits for this case using a p - chart.

problem 2

Processing new accounts at a bank is intended to average 10 minutes each.

Construct upper and lower control limits for:

a) a mean ()(X)) chart

b) a range chart ()(R)) :

	Sample Number
	Sample 1	Sample 2	Sample 3	Sample 4
1	10.20	10.30	9.70	9.90
2	9.90	9.80	9.90	10.30
3	9.80	9.90	9.90	10.10