Historically, the Average Proportion of Defective Bars Has Been 0

question 202

Multiple Choice

Historically, the average proportion of defective bars has been 0.015. Samples will be of 100 bars each. Construct a p- chart using z = 3. Suppose a sample had 0.04 defective. What would you do?

• A) Look for assignable causes.
• B) Change z to 4 and continue sampling.
• C) Nothing; it appears to be random variation.
• D) Change z to 2 and take another sample.