problemas

Actividad 9

Resolver los siguientes ejercicios:

1 The thickness of a printed circuit board is an important quality parameter. Data on board thickness (in inches) are given below, for 25samples of three boards each. (30 puntos)
Sample Number
X1
X2
X3
1
0.0629
0.0636
0.0640
2
0.0630
0.0631
0.0622
3
0.0628
0.0631
0.0633
4
0.0634
0.0630
0.0631
5
0.0619
0.0628
0.06306
0.0613
0.0629
0.0634
7
0.0630
0.0639
0.0625
8
0.0628
0.0627
0.0622
9
0.0623
0.0626
0.0633
10
0.0631
0.0631
0.0633
11
0.0635
0.0630
0.0638
12
0.0623
0.0630
0.0630
130.0635
0.0631
0.0630
14
0.0645
0.0640
0.0631
15
0.0619
0.0644
0.0632
16
0.0631
0.0627
0.0630
17
0.0616
0.0623
0.0631
18
0.0630
0.0630
0.0626
19
0.0636
0.0631
0.0629
20
0.06400.0635
0.0629
21
0.0628
0.0625
0.0616
22
0.0615
0.0625
0.0619
23
0.0630
0.0632
0.0630
24
0.0635
0.0629
0.0635
25
0.0623
0.0629
0.0630

a. Set up and R control charts. Is theprocess in statistical control?
b. Estimate the process standard deviation.
c. Si las especificaciones son 0.0630 0.0015, indique
i) Porcentaje de defectuosos
ii) Índice Cp y su conclusion
iii)Ïndice Cpk y su conclusión


2 Samples of n=8 items each are taken from manufacturing process at regular intervals. A quality characteristic is measured, and and R values are calculated for eachsample. After 50 samples, we have
and

Assume that the quality characteristic is normally distributed (30 puntos)
a. Compute control limits for the and R control charts
b. All points on bothcontrol charts fall between the control limits computed in part (a). What are de natural tolerance limits of the process?
c. Si los límites de especificación son 41 5, ¿qué conclusions ofrece sobre lacapacidad del proceso?
d. ¿Que porcentaje de piezas se tiene que retrabajar porque excedieron el límite superior?
e. ¿QUé porcentaje de piezas se determinan como desperdicio por queda debajo de...