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Confidence interval for mean

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A random sample of 81 credit sales in a department store showed an average sale of $68.00. Historically, it is known that the standard deviation of the population is $27.00. a) determine the standard error of the mean, b) with a 0.95 probability, what can be said about the margin of error and c) what is the 95% confidence interval of the population mean?

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The solution provides step by step method for the calculation of confidence interval for mean . Formula for the calculation and Interpretations of the results are also included.

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Margins of error
A random sample of 81 credit sales in a department store showed an average sale of $68.00. Historically, it is known that the ...

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