During a Year When There Was a Bad Flu Epidemic

Essay

During a year when there was a bad flu epidemic, a school district sampled 30 student records to get an estimate of the mean number of absences of all of the students. The absences recorded were
$\begin{array}{l}\begin{array}{lllllllllllllll}1 & 2 & 3 & 3 & 6 & 6 & 6 & 7 & 7 & 7 & 7 & 8 & 11 & 11 & 12\\13&13&14&14&14&15&16&17&18&19&19&21&22&23&25 \\\end{array} \\\end{array}$
The sample mean is 12.0 absences and the standard deviation is 6.6384. Find a 95% confidence interval for the population mean to two decimal places..