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bachelor in business administration
Polytechnic State University Sanluis
Jan-2006 - Nov-2010
CPA
Polytechnic State University
Jan-2012 - Nov-2016
Professor
Harvard Square Academy (HS2)
Mar-2012 - Present
The branch manager of a nationwide bookstore chain wants to study characteristics of her store s customers. She decides to focus on two variables: the amount of money spent by customers and whether the customers would consider purchasing educational DVDs relating to graduate preparation exams, such as the GMAT, GRE, or LSAT. The results from a sample of 70 customers are as follows:
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a. Construct a 95% confidence interval estimate of the population mean amount spent in the bookstore. b. Construct a 90% confidence interval estimate of the population proportion of customers who would consider purchasing educational DVDs.
Assume that the branch manager of another store in the chain wants to conduct a similar survey in his store. Answer the following questions:
c. What sample size is needed to have 95% confidence of estimating the population mean amount spent in his store to within ±$2 if the standard deviation is assumed to be $10?
d. What sample size is needed to have 90% confidence of estimating the population proportion who would consider purchasing the educational DVDs to within ±0.04?
e. Based on your answers to (c) and (d), how large a sample should the manager take?
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