# statistics

posted by Anonymous

A sample of 25 different payroll depts. 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 by employees in all payroll departments?

1. PsyDAG

90% = mean ± 1.645 SEm

SEm = SD/√n

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