The branch manager of a pet supply store wants to study characteristics of customers of his store. In particular, he decides to focus on two variables: the amount of money spent by customers and whether the customers own only one cat.

1. If he wants to have 95% confidence of estimating the true population mean amount spent in his store within ± $1.50 and the standard deviation is assumed to be $10, what sample size is needed with calculations?

2. If he wants to have 90% confidence of estimating the population proportion of customers who own only a cat to within ± 0.045, what sample size is needed with calculations?

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1. If he wants to have 95% confidence of estimating the true population mean amount spent in his store within ± $1.50 and the standard deviation is assumed to be $10, what sample size is needed with calculations?

Solution. Assume that the standard ...

Solution Summary

The solution consists of details of how to find out the minimum sample size.

... 0.3)^2 That is, n > 1536.9401 Thus the minimum sample size required is ... Result Sample Size Needed 1537. ... The expert finds the sample amount for population means. ...

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