Question

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 12% 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 133 bags and finds that 20 of them are over-filled. He plans to test the hypotheses H 0 : p = 0.12 versus H a : p > 0.12. What is the test statistic? z = (Please round your answer to two decimal places if necessary.)

Answer 1

Given n=133 x = 20 = P = 3 = 20 = 0.1504 The null and alternative hypotheses are Ho: P = 0.12 vs Ha: P30.12 The test statistic is za P-P where PO P=0.12 0.1504 - 0.12 Q -P=0.88 0,12X0.88 133 - l = 1.08