A furniture company received lots of round chairs with the lots size of 6000. The average number of nonconforming chairs in each lot is 15. The inspection of the round chairs is implemented under the ANSI Z1.4 System.
(a) Develop a single sampling plan for all types of inspection.
(b) Identify the required condition(s) for undergoing the reduced inspection.

(c) Twenty lots of the round chairs are received. The initial 10 lots of samples are all accepted with 2
nonconforming chairs found. Assuming the product is stable and cutting the inspection cost is always
desirable by the management, suggest the inspection types and decisions of the other 10 lots with the relative number of nonconforming chairs to be found?

Where the nonconforming units found(d) in :
11th=0 ;12th=1 ; 13th=1 ; 14th=1 ; 15th= 2 ;
16th=1 ;17th=4 ; 18th=2 ; 19th=1 ; 20th=3