# The branch manager ofan outlet (store i) ofa nationwide chain of pet

Question 8.73The branch manager ofan outlet (Store I) ofa nationwidechain of pet supply stores wants to study characteristicsof her customers. In particular, she decides to focus ontwo variables: the amount of money spent by customers andwhether the customers own only one dog, only one cat, ormore than one dog and/or cat. The results from a sample of70 customers are as follows:• Amount of money spent: X \$2 1.34, S \$9.22.• 37 customers own only a dog.• 26 eustomers own only a cat.• 7 customers own more than one dog and/or cat.a. Construct a 95% confidence interval estimate for thepopulation mean amount spent in the pet supply store.b. Construct a 90% confidence interval estimate for thepopulation proportion of customers who own only a cat.The branch manager of another outlet (Store 2) wishes toconduct a similar survey in his store. The manager does nothave access to the information generated by the manager ofStore I. Answer the following questions:c. What sample size is needed to have 95% confidence ofestimating the population mean amount spent in this storeto within ± \$1.50 if the standard deviation is estimated tobe \$10?d. How many customers need to be selected to have 90%confidence of estimating the population proportion ofcustomers who own only a cat to within ±0.045?e. Based on your answers to (c) and (d),

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