Determine necessary control limits - quality and performance

Assignment Help Advanced Statistics

Reference no: EM13187116

1. The Young Company produces plastic bottles to customer order. The quality inspector randomly selects four bottles from the bottle machine and measures the outside diameter of the bottle neck, a critical quality dimension that determines whether the bottle cap will fit properly. The dimension (in.) from the last six samples are

	Bottle
Sample	1	2	3	4
1	0.604	0.612	0.588	0.600
2	0.597	0.601	0.607	0.603
3	0.581	0.570	0.585	0.592
4	0.620	0.605	0.595	0.588
5	0.590	0.614	0.608	0.604
6	0.585	0.583	0.617	0.579

a) Assume that only these six samples are sufficient, and use the data to determine the necessary control limits.

b) Suppose the specification for the bottle neck diameter is 0.600 +/- 0.050 inches. If the population standard deviation is 0.013 inches, and the firm is seeking four-sigma quality, is the process capable of producing the bottle?

2. As a hospital administrator of a large hospital, you are concerned with the absenteeism among nurses' aides. The issue has been raised by registered nurses, who fell they often have to perform work normally done by their aides. To get the facts, absenteeism data was gathered for the last three weeks, which is considered a representative period for future conditions. After taking random samples of 64 personnel files each day, the following data were produced:

Day	Aides Absent
1	4
2	3
3	2
4	4
5	2
6	5
7	3
8	4
9	7
10	2
11	3
12	2
13	1
14	3
15	4

Because your assessment of absenteeism is likely to come under careful scrutiny, you would like a type 1 error of only 1 percent. You want to identify any instances of unusual absenteeism. If some is present, you will have to explore them on behalf of the registered nurses.

a) Design the appropriate control chart.

b) Based on your chart and the data from the last 3 weeks, what can you conclude about the absenteeism of nurses' aides?

3. A textile manufacturer wants to set up control charts for irregularities (e.g. oil stains, shop soil, loose threads, etc.) per 100 square yards of carpet. The following data were collected form a sample of 20 100-square-yard pieces of carpet

Sample	Irregularities
1	11
2	8
3	9
4	12
5	4
6	16
7	5
8	8
9	17
10	10
11	11
12	5
13	7
14	12
15	13
16	8
17	19
18	11
19	9
20	10

a) Using these data, set up a c-chart with z = 3.

b) Suppose that the next five samples had 15, 18, 12, 22 and 21 irregularities. What would you conclude?

4. A critical dimension of the service quality of a call center is the wait time of a caller to get a sales representative. Periodically, random samples of three customer calls are measured for time. The results of the last four samples are in the following table:

Sample	Time (sec)
1	495	501	498
2	512	508	504
3	505	497	501
4	496	503	492

a) Assuming that management is willing to use three-sigma control limits, and using only the historical information contained in the four samples, show that the call center access time is in statistical control.

b) Suppose that the standard deviation of the process distribution is 0.577. If the specifications for the access time are 500 +/- 18 seconds, is the process capable? Why or why not? Assume three-sigma quality.

Reference no: EM13187116

Questions Cloud

How much is tax for social security and medicare combined : Molly Flynn , an accountant fo Coor Corporation, earns $106,200 from January to June. In July, Molly earned $8,000. Assume a tax rate of 6.2% for Social Security on $106,800 and Medicare of 1.45%. How much is the tax for Social Security and Medica..

What is a graph that shows d versus v : If a cylindrical container is filled to a depth of d cm by pouring in V cc of liquid, what is a graph that shows d versus V?

State sample of hydrocarbon compund containing only c : A 6.52 g sample of hydrocarbon compund containing only C and hydrogen produced 20.5 g of CO2. A 9.29 ml sample weighing 21.6 mg was collected over water at a pressure of 796 torr at 25 C

How would a decrease in the reserve requirement effect : How would a decrease in the reserve requirement effect the (a) size of the money multiplier (b) amount of excess reserves in the banking system and (c) extent to which the system could expand the money supply through the creations of checkable dep..

Determine necessary control limits - quality and performance : Design the appropriate control chart - based on your chart and the data from the last 3 weeks, what can you conclude about the absenteeism of nurses' aides

State how many moles of khp were weighed out : How many moles of KHP were weighed out? How many moles of NaOH were required to neutralize the KHP that was weighed out?

Definition of loyalty is conformity : What does Henry Steele Commager mean when he writes that the new definition of loyalty is "conformity"?

State what is the normality of a solution prepared : What is the normality of a solution prepared from 10 ml 0.6 N nitric acid by diluting it to 60 ml

Discuss the five economic principles : Select one principle and create an additional example that will help students understand that principle better. Based on the five economic principles discussed, give your opinion on the one which is the most important and useful concept in your lif..

User Account

All Pages