# Confidence interval

A sample of 25 different payroll departments found that the employees worked an average of 310.3 days a year with a standard deviation of 23.8 days. What is the 90% confidence interval for the average days worked, population mean, of all payroll departments?

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A sample of 25 different payroll departments found that the employees worked an average of 310.3 days a year with a standard deviation of 23.8 days. What is the 90% confidence interval for the average days worked, population mean , of all payroll departments?

90% ...

#### Solution Summary

Finds 90% confidence interval for the average days worked.

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