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Confidence Interval for Population Means

The Human Resources Department is considering offering employees a dental plan, and as part of their analysis must estimate how much the employee and her or her family spends on dental expenses each year. They take a random sample of 64 employees, and find that the mean amount spent last year was $2,150, with a standard deviation of $720.

a) Construct a 95% confidence interval for the population mean.

b) When the VP of Finance sees the estimate, he says "This is too wide -- I need for the estimate to be more precise." What do you do?

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