Question $6.$ Dissolved Oxygen Concentration:

An article in the ASCE Journal of Energy Engineering $["$Overview of Reservoir Release Improvements at $20$ TVA Dams" $($Vol$.125,$ April $1999,$ pp$.1-17)]$ presents data on dissolved oxygen concentrations in streams below $20$ dams in the Tennessee Valley Authority system. The observations are $($in milligrams per liter$)$: $5\mathrm{.}0,3\mathrm{.}4,3\mathrm{.}9,1\mathrm{.}3,0\mathrm{.}2,0\mathrm{.}9,2\mathrm{.}7,3\mathrm{.}7,3\mathrm{.}8,4\mathrm{.}1,1\mathrm{.}0,1\mathrm{.}0,0\mathrm{.}8,0\mathrm{.}4,3\mathrm{.}8,4\mathrm{.}5,5\mathrm{.}3,6\mathrm{.}1,6\mathrm{.}9,$ and $6\mathrm{.}5.$ Test the hypothesis $H_0$:$=4$ versus $H_1$:$4.$ Use $=0\mathrm{.}01.$ Is it possible to reject $H_0$ hypothesis at the $0\mathrm{.}01$ level of significance? Find the $P-$value.