Statistical Quality Control Stat class 1) For a single-sampling plan for attributes, what do the following symbols represent?
a. N
b. n
c. c
d. d
2) For a double-sampling plan for attributes, what do the following symbols represent?
a. n1
b. n2
c. c1
d. c2
e. d1
f. d2

Step-by-step explanation:

In a single - sampling plan, when a decision on acceptance / rejection of the lot  is made on the basis of  only one sample, Then , the acceptance plan is said to be a single sampling plan. The single sampling plan is known as the most common and easiest sampling plan

The following symbol representation can be written as follows:

a. N    →   Lot size   from which the sample is drawn

b. n    →    sample size

c. c    →     acceptance number

d. d   →    number of defectives in the sample

For example:

if we take a  randomized sample of  size 'n' from the Lot size.

The next step will be to inspect all items in the sample to find the defectives 'd'

The decision rule is that:

If  the number of defectives is less than or equal to acceptance number, then answer is YES i.e d ≤ c, Then ,  we accept the Lot

If the number of defectives is not less than or equal to acceptance number, then the answer is NO . Then , we reject the Lot.

So if we reject, we either do 100% inspection or return the lot to the supplier.

In a double sampling plan , the decision on acceptance/rejection  of the Lot is based on two samples.

The following symbol representation can be written as follows:

a. n1    →  number of size of sample 1

b. n2    → number of size of sample 2

c. c1    →  acceptance number for sample 1

d. c2    →  acceptance number for sample 2

e. d1    →  number of defectives in sample 1

f. d2   →  number of defectives in sample 2