Question 1

The fundamental interpretation of an AOQ curve is that
A)all defects can be detected if beta is small enough
B)the worse the lot being tested,the more likely it is to fail inspection
C)it is unwise to expect acceptance sampling to remove all defects
D)the best AOQ rates are for very good lots and for very bad lots;the worst AOQ rates are for lots with "in-between" quality

Accepted Answer

The AOQ curve shows the tradeoff between the probability of accepting a lot with defects (producer's risk) and the probability of rejecting a lot that is actually conforming (consumer's risk) for different lot qualities. The best AOQ rates are for very good and very bad lots, as the inspection can easily identify them as conforming or non-conforming. However, for lots with "in-between" quality, it is harder to identify the defects and the AOQ rates are worse. Therefore, the correct interpretation is given in choice D.

Question 2

A multiple-sampling plan is used instead of single- and double- sampling plans because
A)it insures the highest level of quality
B)it requires the largest sample sizes
C)It requires the smallest sample sizes
D)It has the highest probability of detecting a bad lot

Accepted Answer

Multiple-sampling plans often require smaller sample sizes overall compared to single- or double-sampling plans because they allow for early acceptance or rejection based on the results of initial samples, potentially reducing the number of items that need to be inspected.

Question 3

The inputs to determining a sampling plan are
A)alpha and beta,n and p
B)alpha,beta,producer's risk and consumer's risk
C)alpha,beta,AQL,and LTPD.
D)lot size,sample size,AQL and LTPD

Accepted Answer

The inputs required to determine a sampling plan are alpha (Type I error), beta (Type II error), Acceptable Quality Level (AQL), and Lot Tolerance Percent Defective (LTPD). Alpha and beta are used to determine the sample size, while AQL and LTPD are used to determine the acceptance or rejection of a lot. Therefore, option C is the best choice. The other options include incorrect inputs or do not cover all the necessary inputs.

Question 4

The output of a sampling plan is
A)lot size and actual number of defects in a sample
B)sample size and acceptable number of defects in a sample
C)acceptance quality level and lot tolerance percent defective
D)consumer's risk and producer's risk

Accepted Answer

A sampling plan typically specifies the sample size and the acceptable number of defects in that sample to determine if the entire batch meets the quality standards.

Question 5

AOQL is
A)the Absolute Overall Quality Limit
B)the Absolute Outgoing Quality Level
C)the Average Outgoing Quality Limit
D)the Average Outgoing Quantity Level

Accepted Answer

AOQL stands for Average Outgoing Quality Limit, which represents the acceptable level of defects or errors in a production batch. It is a statistical tool used to measure quality control and ensure that a certain level of quality is maintained in the outgoing products. Option A and B are not correct as there is no term as "Absolute Overall Quality Limit" or "Absolute Outgoing Quality Level" used in quality control. Option D is also not correct as there is no term as "Average Outgoing Quantity Level" used in quality control.

Question 6

An operating characteristics curve
A)shows the probability of accepting a lot with various percent defectives
B)considers that defective items are replaced with good items
C)is used for double sampling
D)can be developed separately from a sampling plan

Accepted Answer

An operating characteristics curve shows the probability of accepting a lot with various percent defectives. It is used to evaluate the performance of a sampling plan and helps determine the risk of accepting a lot with a given level of defectives. It takes into account the sample size, acceptance number, and the level of inspection required. It is specific to a given sampling plan and cannot be developed separately from it.

Question 7

The probability of accepting a bad lot is known as
A)Type I error
B)Type II error
C)acceptable quality level
D)producer's risk

Accepted Answer

Type II error refers to the error made when a false null hypothesis is not rejected. In the context of quality control, accepting a bad lot (i.e., failing to reject a bad batch of products) is analogous to a Type II error, where the 'null hypothesis' would be that the lot does not meet quality standards.

Question 8

Setting alpha equal to 5 percent
A)means that five percent of all items are defective
B)means that five percent of all samples will fail testing
C)is required by OM Tools
D)means that when a batch is better than AQL,there is a five percent chance it will fail testing

Accepted Answer

Setting alpha equal to 5 percent means that when a batch is better than AQL, there is a 5 percent chance it will still fail testing. This is because alpha represents the probability of a Type I error, which is the rejection of a good batch. The other options are not correct as they do not accurately reflect the meaning of alpha in a statistical context.

Question 9

A double-sampling plan is used instead of a single-sampling plan in order to
A)verify the results of a single-sampling plan
B)allow fewer defective items to be accepted
C)provide a higher level of quality than a single-sampling plan
D)save costs

Accepted Answer

Double-sampling plans can save costs by potentially reducing the number of items that need to be inspected compared to a single-sampling plan. If the results of the first sample are conclusive, there is no need for a second sample, thus saving inspection time and costs.

Question 10

AOQ is at its worst level when
A)the product is especially poor in quality
B)AQL equals LTPD
C)the sample size n is small
D)product is neither exceptionally good nor exceptionally poor in quality

Accepted Answer

AOQ (Average Outgoing Quality) is at its worst when the product quality is neither exceptionally good nor poor, as this leads to more variability and potential defects slipping through.

Quiz 5: Supplement Operational Decision-Making Tools: Acceptance Sampling

The fundamental interpretation of an AOQ curve is that

A multiple-sampling plan is used instead of single- and double- sampling plans because

The inputs to determining a sampling plan are

The output of a sampling plan is

AOQL is

An operating characteristics curve

The probability of accepting a bad lot is known as

Setting alpha equal to 5 percent

A double-sampling plan is used instead of a single-sampling plan in order to

AOQ is at its worst level when