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Qnt/561 Applied Business Research & Statistics

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Applied Research and Statistics QNT561 Research and Sampling Designs Shindeera Robinson June 21, 2010 Chapter 8 21. What is sampling error? Could the value of the sampling error be zero? If it were zero, what would this mean? Sampling error is the difference between the statistic estimated from a sample and the true population statistic. While we would expect the sampling error to not be zero, it is not impossible. For example if you were evaluating the ethnicities of a population and everyone in the population was Caucasian then taking any sample would give you the true proportion of 100% Caucasian. In other words, if the sampling error is zero then the population is uniform or you were taking a perfectly representative sample …show more content…

Would it be reasonable to conclude that more than 10 percent of the applicants are now failing the test? In addition to the testing of applicants, Fashion Industries randomly tests its employees throughout the year. Last year in the 400 random tests conducted, 14 employees failed the test. Would it be reasonable to conclude that less than 5 percent of the employees are not able to pass the random drug test? Proportion is 14/220 = 0.064 Confidence interval= 0.064 +/- 2.575*sqrt(.064*.936/220) = (0.0215, 0.1065) 28 people who failed 620 tests= 0.0452 Critical values= 2.575 and -2.575 z = (0.0452-0.05)/sqrt(0.05*0.95/620)=-0.548. 0.548 employees and not pass the random drug test. Yes I can conclude that less than 5 percent of the employees are not able to pass the random drug test References: Fridah, M. (n.d.). Sampling In Research. Retrieved June 21, 2010, from http://www.socialresearchmethods.net/tutorial/Mugo/tutorial.htm Lind, D. A. (2005). Statistical Techniques in Business & Economics (12 ed.). New York: The

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