Test Hypotheses Regarding Two Population Standard Deviations
-A University Wants $\alpha = 0.05$

Test Hypotheses Regarding Two Population Standard Deviations
-A university wants to see whether there is a significant difference in the variances of the ages between day staff and night staff. A random sample of 31 staff members is selected from each group. The data are given below. Test the hypothesis that there is no difference in age between the two groups.
Use $\alpha = 0.05$ .
Day Staff
$\begin{array} { l l l l l l l l l l l } 22 & 24 & 24 & 23 & 19 & 19 & 23 & 22 & 18 & 21 & 21 \\ 18 & 18 & 25 & 29 & 24 & 23 & 22 & 22 & 21 & 20 & 20 \\ 20 & 27 & 17 & 19 & 18 & 21 & 20 & 23 & 26 & & \end{array}$
Evening Staff
$\begin{array} { l l l l l l l l l l l } 18 & 23 & 25 & 23 & 21 & 21 & 23 & 24 & 27 & 31 & 34 \\ 20 & 20 & 23 & 19 & 25 & 24 & 27 & 23 & 20 & 20 & 21 \\ 25 & 24 & 23 & 28 & 20 & 19 & 23 & 24 & 20 & & \end{array}$
Assume the samples were randomly selected from normal populations.