Historically, the Average Proportion of Defective Bars Has Been 0 $$z = 3$$

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 0.054 defectives. What would be the best action to take in this scenario?

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