A quality control engineer at a potato chip company tests the bag filling machine by weighing bags of potato chips. Not every bag contains exactly the same weight. But if more than 15% of bags are over-filled then they stop production to fix the machine. They define over-filled to be more than 1 ounce above the weight on the package.

The engineer weighs 100 bags and finds that 21 of them are over-filled. He plans to test the hypotheses H₀:p=0.15 versus H_a:p>0.15.

What is the test statistic?

Responses

Z=1.68

Z=-1.68

Z=-1.47

Z=4