Assume that 4% of items produced in an assembly line operation are defective, but the production manager of the firm is not aware of this situation.

Assume further that 144 parts are tested by the quality assurance department in order to determine the quality of the assembly operation let p be the sample proportion of items found defective by the quality assurance test.

If the test shows p = 0.08 r more, then the assembly line will be shut down to check for the cause of defects. what is the probability that the sample of 144 parts will lead to the conclusion that the assembly line will be shut down?