Many employers are concerned about employees wasting time by surfing the Internet and e-mailing friends during work hours. The article "Who Goofs Off 2 Hours a Day? Most Workers, Survey Says" summarized data from a large sample of workers. + Suppose that the CEO of a national marketing firm wants to determine the difference in mean wasted time during an 8 -hour workday for employees of her company at two different locations. Each person in a random sample of 10 employees from Location A (population 1) is asked about daily wasted time at work (in minutes), and 10 employees from Location B (population 2) are asked the same question. Participants were guaranteed anonymity to obtain truthful responses. Suppose the resulting data are as follows. \table[[Location A,90,138,142,102,122,141,111,125,146,76],[Location B,109,104,109,111,102,103,119,117,105,100]] (a) Calculate the point estimate for the difference in the population means.
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11.4 (b) Determine the margin of error for the
90%
confidence interval for the difference in population means. (Use a table or technology. Round your answer to three decimal places.)
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M=(t critical value )\sqrt((s_(1)^(2))/(n_(1))+(s_(2)^(2))/(n_(2)))
(c) Find the
90%
confidence interval. (Round your answers to three decimal places.)
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