Question

1. Use the table below that is provided to determine the probability that a computerized system fails due to a Lack of Training:

Assume all causes of failure of the system are totally independent:

Causes for System Failure	Probability Failure
Design	.40
Practices and Procedures	.20
Lack of Supervision	.10
Lack of Training	.30
Totals	100%

2. Use the table below that is provided to determine the probability that a computerized system fails due to Design or Supervision:

Assume all causes of failure of the system are totally independent:

Causes for System Failure	Probability Failure
Design	.40
Practices and Procedures	.20
Lack of Supervision	.10
Lack of Training	.30
Totals	100%

3. What is the probability that there is no error in the production of masks when a sample of 1,200 masks found that 100 were defective?

Answer 1

a) The probability that a computerized system fails due to a Lack of Training is seen directly from the given probability distribution table as: 0.3. therefore 0.3 is the required probability here.

b) The probability that a computerized system fails due to Design or Supervision is computed here as:
= P(design) + P( supervision)

= 0.4 + 0.1 = 0.5

Therefore 0.5 is the required probability here.

c) Probability of no error here is computed as:
= Number of masks with no error/ Total masks produced

= (1200 - 100) / 1200

= 11/12

Therefore 11/12 is the required probability here.