selects simple random samples of 30 finished products and computes the sample mean product weight. If test results over a long period of time show that 5% of the values are over 2.1 pounds and 5% are under 1.9 pounds, what are the mean and the standard deviation for the population of products produced with this process? Assuming a "Normal" distribution Mean = (1/2)(2.1+1.9) = 2.0 With 5% in each tail, we have 90% in the middle of the distribution. This translates into a z-value of P(Z < z*) = 0.05 has a z* = 1.645 2.0 + (1.645)(s) = 2.1 s = 0.1 / 1.645 = 0.06079 5. In an effort to estimate the mean amount spent per customer for dinner at a major Atlanta restaurant, data were collected for a sample of 49 customers. Assume a population standard deviation of $5. a. At 95% confidence, what is the margin of error? The margin of error is found using the following formula: In order to find the margin of error we need to find first. Since we want a confidence level of 95% this implies that = 5%, which means that = 0.025. =-1.959963986 Margin of error is equal to (-1.9599)(5/(49) = -1.399928571 b. If the sample mean is $24.80, what is the 95% confidence interval for the population mean? σ = 5 x = 24.8 ̅ n= 49 Confidence level = .95 Z Interval (23.4, 26.2) x =24.8 ̅ This study source was downloaded by 100000829219024 from CourseHero.com on 08-1

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Week 2, Individual Work 24. Number on a football player’s jersey The number on a football player’s jersey would be qualitative because the jersey number would be characteristic. 32. Number of ... sequoia trees in a randomly selected acre of Yosemite National Park Would be a discrete variable because the number of sequoia trees would be countable if one acre is squared off in Yosemite National Park. 34. Internet connection speed in Kilobytes per second The Internet speed in Kilobytes would be continuous because it would have an infinite number of possible values that are not countable. 52. BMW cars the following information relates to the 2008 model year product line of automobiles. Model Body Style Weight (lb) Number of Seats 3 series Coupe 3,351 4 5 Series Sedan 3,505 5 6 Series Convertible 4,277 4 7 Series Sedan 4,486 5 X3 Sport Utility 4,012 5 Z4 Roadster Coupe 3,087 2 This information represents qualitative variable because the information characterizes the cars shown. 58. Financial Worries? Gallup News Service conducted a survey of 1,006 American adult aged 18 years or older. September 24-27, 2007. The respondents were asked, “What, if anything, [Show More]

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