Qnt_571_Week_2

Ch 8. #21. Sampling error is the amount of error in sampling a portion of the population, instead of the entire population. Sampling error can be reduced by sampling a large amount of the population, and using a random sample or stratified sample of populations. If the sampling error is ‘0’, this theoretically means that the sample represented an accurate portion of the population, or by sampling the entire population. Ch. 8 #22 The reasons for sampling include: saving time and not having to observe/contact the entire population; sampling all items in the population may be prohibitive; physically impossible to question the entire population, some tests may be destructive; proportion of samples make the results adequate. Ch 8. #34. A. St. Dev divided by the square root of the sample = 40,000/square root of 50.0 = 5656.8 B. The expected shape will be a bell curve C. P (X-u) / (o) > 112000 – 110000/40,000 = P (z > 0.05) 1 – 0.5199 = 0.4801 D. Sample mean of more than 100,000 but less than 112,000' = P (100000 < X < 112,000) = P (100000-110000/40000 < X – u/o < 112000 -110000/40000) = 0.5199 – 0.4013 = 0.1186 Ch. 9 #32 a. Estimated population mean would be 3.01 lbs b. Confidence interval = invT (0.975, 35) * 0.03/square root of 36 = 0.0102 CI of 95% = 3.01 - .0102 < u < 3.01 + .0102 #34 a. mean – z*stdev/squart root (N) to mean+ z *stdev/square root of N z = 1.96 N = 50 stdev = 6.2 mean = 26 26 – 1.96*6.2/squart root (50) to 26 + 1.96*6.2/square root (50) = 24.28 to 27.72 having 28 weeks as the mean would not be likely because it is outside the 95% confidence interval. The mean should be within 24 weeks to 27 weeks. #46. 14/220 =0.64 sample proportion 14/220 – 2.5758 * sq (14/220)*1-14/220)/220) to 12/220 + 2.5758 * sqrt(14/220) * ( 1-14/220)/220) = 0.0212 to 0.1060 B. 10% is within the confidence interval, and it is reasonable. Second half 14/400 - 2.5758*sqrt(14/400*(1-14/400)/400) to 14/220 + 2.5758*sqrt(14/400*(1-14/400)/400) = 0.01133 to 0.05866 It’s not reasonable that 5% fail the test. Ch 3. DQ #5 You have been approached by the editor of Gentlemen's Magazine to carry out a research study. The magazine has been unsuccessful in attracting shoe manufacturers as advertisers. When the sales force tried to secure advertising from shoe manufacturers, they were told men's clothing stores are a small and dying segment of their business. Since Gentlemen's Magazine goes chiefly to men's clothing stores, the manufacturers reasoned that it was, therefore, not a good vehicle for their advertising. The editor believes that a survey (via mail questionnaire) of men's clothing stores in the United States will probably show that these stores are important outlets for men's shoes and are not declining in importance as shoe outlets. He asks you to develop a proposal for the study and submit it to him. Develop the management-research question hierarchy that will help you to develop a specific proposal. - Most importantly we need to ask ourselves why men’s clothing stores are a small and dying segment of the shoe manufacturer business. We need to find a way to market Gentlemen’s Magazine to show manufacturers. What profit sizes are shoe manufacturers looking at' What types of sales sources are show manufacturers using currently' Of the clothing stores our magazine is distributed, what percentage of their sales are shoes' What is the demand of men shoes and what are the sales of shoes' Will adding men’s shoes be profitable for Gentlemen’s magazine' Second we will need to ask our customers how often they purchase men’s shoes' What type/style of shoes are they looking to purchase' If they were made aware of different types of shoes while clothes shopping, would they be likely to buy a new pair of shoes to go with their new suit/outfit'