A dairy has to control the amount of butterfat in its low-fat milk. The upper specification limit of the fat content is 4 g for 4-L containers. The standard deviation of the fat content for these containers is estimated to be 0.5 g. It is desired to accept 95% of the shipments when the proportion of containers that are nonconforming is 1%.
Additionally, when 7% of the containers are nonconforming, the probability of acceptance is desired to be 8%. Find the parameters of a variable sampling plan and explain its operation, assuming that the first condition is to be satisfied exactly.
A random sample of 13 containers yielded an average fat content of 3.05 g. What is the decision regarding the lot? Demonstrate the use of Forms l and 2.