a sample of 800 computer chips revealed that 69% of the chips do not fail in the first 1000 hours of their use. the company's promotional literature states that 67% of the chips do not fail in the first 1000 hours of their use. the quality control manager wants to test the claim that the actual percentage that do not fail is different from the stated percentage. find the value of the test statistic. round your answer to two decimal places.