Question

Part 1

A regional airline is concerned about its on-time performance. The Memphis hub experiences 20 flight operations each day of the week, with the following record of on-time departures for the previous 10 days: 17, 16, 18, 19, 16, 15, 20, 17, 18, and 16. Prepare a p-chart with a sample size consisting of one week’s average on-time percentage.

	a.	UCL = .86, LCL = 0
	b.	UCL = .93, LCL = 0
	c.	UCL = 1, LCL = .47
	d.	UCL = 1.25, LCL = .47
	e.	None of the above

Part 2.

A process is considered to be out of control when:

	a.	Sample measurements show wide variance.
	b.	A measurement falls outside the control limits.
	c.	The sample mean is above the population mean.
	d.	Sample measurements follow a distinct pattern within the control limits.
	e.	None of the above.

Part 3.

In a service firm, which of the following would be an example of a prevention cost?

	a.	Inspection
	b.	Process control
	c.	Collecting quality data
	d.	Recruitment and selection
	e.	Scrapped forms and reports

Final Part.

Doing work incorrectly is an example of a:

	a.	Task error
	b.	Tangible error
	c.	Resolution error
	d.	Encounter error
	e.	Treatment error

Answer 1

Part 1:

Here, Correct Answer is  

d.	UCL = 1.25, LCL = .47

Others options are not matching with below calculation, thus, others options are eliminated,  

Important Formula: formula for P Bar = Sum of P value/Sum of Sample Size over 10 days

Factor = 3 *square root of (((1-Pbar)/Par)/n) here, n = 7 days

UCL of P Chart = P Bar + Factor

LCL of P Chart = P Bar - Factor

1	B	C	D	E
2		Sample Size	On Time Departure	P or Proportionate Calculation
3		20	17	0.85
4		20	16	0.8
5		20	18	0.9
6		20	19	0.95
7		20	16	0.8
8		20	15	0.75
9		20	20	1
10		20	17	0.85
11		20	18	0.9
12		20	16	0.8
13	Total	200	172	8.6
14	P Bar for P Chart	0.86
15	n	7
16	Factor Calculation	0.39
17	UCL for P Chart	1.25
18	LCL for P Chart	0.47

Excel Formula:

1	B	C	D	E
2		Sample Size	On Time Departure	P or Proportionate Calculation
3		20	17	=D3/C3
4		20	16	=D4/C4
5		20	18	=D5/C5
6		20	19	=D6/C6
7		20	16	=D7/C7
8		20	15	=D8/C8
9		20	20	=D9/C9
10		20	17	=D10/C10
11		20	18	=D11/C11
12		20	16	=D12/C12
13	Total	=SUM(C3:C12)	=SUM(D3:D12)	=SUM(E3:E12)
14	P Bar for P Chart	=D13/C13
15	n	7
16	Factor Calculation	=3*SQRT((C14*(1-C14))/C15)
17	UCL for P Chart	=C14+C16
18	LCL for P Chart	=C14-C16

Part 2:

Here, Correct answer is

b.	A measurement falls outside the control limits.

Explanation:

Any process can be considered as out of control if that process data having special cause or any data points fall outside the UCL and LCL Value, thus, Option B is Correct and sample measurements can follow district pattern or random pattern within the control limits, here, Process could be in control, Sample Measurements could have wide variance, but data could be in between UCL and LCL value, thus, these options are not correct, sample mean has more value over population mean is not correlated here,

Here, Correct answer is b. process control

Explanation:

The Example of Prevention cost for a service firm is Process control or statistical process control or SPC, Inspection is appraisal cost, thus, can’t be considered as Prevention cost, others options are not correlated to prevention cost, thus, others options are eliminated

Final Part:

Here, Correct answer is a. Task Error,

Doing Work incorrectly and doing the work poor way, in wrong order, and doing any work, which is not even requested, such event can be taken as example of Task Error, and others options are not correlated with the above question, thus others options are eliminated,