An analyst in a personnel department randomly selects the records of 16 hourly employees and finds that the mean wage rate per hour is $9:50. The wage rates in the firm are assumed to be normally...

An analyst in a personnel department randomly selects the records of 16 hourly employees and finds that the mean wage rate per hour is $9:50. The wage rates in the firm are assumed to be normally distributed. If the standard deviation of the wage rates is known to be $1:00, estimate the mean wage rate in the firm using an 80 percent confidence interval.