Answer
σ is between 3.61 and 12.33
Work Step by Step
$\alpha=1-0.95=0.05.$ By using the table we can find the critical chi-square values with with $df=sample \ size-1=7-1=6$.
$X_{L}^2= X_{0.975}^2=1.237$
$ X_{R}^2= X_{0.025}^2=14.449$
Hence the confidence interval:$\sigma$ is between $\sqrt{\frac{(n-1)\cdot s^2}{ X_{R}^2}}=\sqrt{\frac{(6)\cdot 5.6^2}{14.449}}=3.61$ and $\sqrt{\frac{(n-1)\cdot s^2}{ X_{L}^2}}=\sqrt{\frac{(6)\cdot 5.6^2}{1.237}}=12.33.$
