공업통계학 principles of statistics for engineers and scientists 7.1 7.2 7.3 7.4 8.1 8.2 8.3장 연습문제 풀이
- 최초 등록일
- 2017.03.02
- 최종 저작일
- 2014.12
- 13페이지/
한컴오피스
- 가격 2,500원
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본문내용
A sample of 45 room air conditioners of a certain model had a mean sound pressure of 52 decibels (dB) and a standard deviation of 5 dB, and a sample of 60 air conditioners of a different model had a mean sound pressure of 46 dB and a standard deviation of 2 dB. Find a 98% confidence interval for the difference in mean sound pressure between the two models.
<중 략>
Two corrosion inhibitors, one more expensive than the other are being considered for treating stainless steel. To compare them, specimens of stainless steel were immersed for four hours in a solution containing sulfuric acid and corrosion inhibitor. Thirty-eight specimens immersed in the less expensive product had an average weight loss of 242 mg and a standard deviation of 20 mg, and 42 specimens immersed in the more expensive product had an average weight loss of 180 mg and a standard deviation of 31 mg. It is determined that the more expensive product will be used if it can be shown that its additional mean weight loss over that of the less expensive method is greater than 50 mg.
참고 자료
공업통계학 principles of statistics for engineers and scientists
