Question

Problem 1: Explain how 6-Sigma differs from traditional quality control.

Problem2: Can a product achieve a quality of design but not a quality of conformance?

Problem 3

A teller at a drive-up window at a bank had the following service times (in minutes) for 20 randomly selected customers:

Sample #1 (10AM-11AM)	Sample #2 (11AM-Noon)	Sample #3 (Noon-1PM)	Sample #4 (1PM-2PM)
4.5	4.6	4.5	4.7
4.2	4.5	4.6	4.6
4.2	4.4	4.4	4.8
4.3	4.7	4.4	4.5
4.3	4.3	4.6	4.9

1. Determine the upper control limit (UCL) of the mean chart.
2. Determine the upper control limit (UCL) of the range chart.

Problem 4

A town's department of public works is concerned about adverse public reaction to a sewer project that is currently in progress. Because of this, the Commissioner of Public Works has authorized a weekly survey to be conducted of town residents. Each week, a sample of 100 residents is questioned on their feelings towards the project. The results to date are shown below. Analyze this data using a P-chart with a 5% risk of Type I error (Z=3). Is the community sentiment stable?

                       

Week	1	2	3	4	5	6	7	8
Opposed	10	8	12	6	4	14	8	10

a) Determine the upper control limit (UCL) of P-chart.

b) Determine the lower control limit (UCL) of P-chart.

c) Is the community sentiment stable?

Problem 5

An appliance manufacturer wants to contract with a repair shop to handle the authorized repair in Grand Forks. The company has set an acceptable range of repair time of 50 minutes to 90 minutes. Two firms have submitted bids for the work. In test trials, one firm had a mean repair time of 74 minutes with a standard deviation of 4.0 minutes, and the other firm had a mean repair time of 72 minutes with a standard deviation of 5.1 minutes.

a)Which firm would you choose?

b) Why?

Answer 1

please rate my answer and comment for doubts.