A retailer that sells porcelain plates has projected sales of 100 plates per month. The monthly holding cost is $2 per plate, and it costs $55 to process a purchase order. If the vendor is willing to offer the manager a discount of $10 per order for ordering in multiples of 50 plates (ex: 50, 100, 150, etc…) would you advise the retailer to take advantage of the offer? If so, what order quantity would you recommend?

Six samples of n=10 observations have been obtained and the sample means and ranges were computed in minutes:

• Determine the upper and lower limits for sample mean and range control charts.
• Is the process in control?

Sample	Mean	Range
1	3.06	0.42
2	3.15	0.5
3	3.11	0.41
4	3.13	0.46
5	3.06	0.46
6	3.09	0.45