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Confidence intervals and Standard Deviation

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Sales personnel for Skillings Distributors submit weekly reports listing the customer contacts made during the week. A sample of 65 weekly reports showed a sample mean of 19.5 customer contacts per week. The sample standard deviation was 5.2. Provide 90% and 95% confidence intervals for the population mean number of weekly customer contacts for the sales personnel.

90% Confidence, to 2 decimals:

( __________ , __________ )

95% Confidence, to 2 decimals:

( __________ , __________ )

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Solution Summary

This solution illustrates the method of determination of confidence intervals.

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We have, 100(1-α)% confidence interval for the population mean is given by,
(please see the attached ...

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