Operations/Financial Management
* Boxes of Organic Flakes are produced to contain 14 ounces, with a standard deviation of .1 ounce. Set up the 3-sigma x-chart for a sample size of 36 boxes.
* Thirty-five samples of size 7 each were taken from a fertilizer-bag-filling machine. The results were: Overall mean = 57.75 lb.; Average range = 1.78 lb.
a) Determine the upper and lower control limits of the x-chart, where o=3.
b) Determine the upper and lower control limits of the R-chart, where o=3.
* The defect rate for data entry of insurance claims has historically been about 1.5%. What are the upper and lower control chart limits if you wish to use a sample size of 100 and 3-sigma limits?
* In the past, the defect rate for your product has been 1.5%, what would be the control limits (z=3)?
* Meena Chavan Corp's computer chip production process yields DRAM chips with an average life of 1,800 hours and o=100 hours. The tolerance upper and lower specification limits are 2,400 hours and 1,600 hours, respectively. Is this process capable of producing DRAM chips to specification?
* As the supervisor in charge of shipping and receiving, you need to determine the average outgoing quality in a plant where the known incoming lots from your assembly line have an average defective rate of 3%. Your plan is to sample 80 units of every 1,000 in a lot. The number of defects in the sample is not to exceed 3. Such a plan provides you with a probability of acceptance of each lot of .79 (79%). What is your average outgoing quality?