The liquid chlorine added to swimming pools to combat algae has a relatively short shelf life before loses its effectiveness. Records indicate that the mean sholf life of a 5-gallon jug of chlorine is 2,160 hours (90 days). As a experiment, Holdlonger was added to the chlorine to find whether it would increase the shelf life. A sample of nine jugs of chlorine had these shelf lives( in hours): df

2159 2170 2180 2179 2160 2167 2171 2181 2185

At the .025 level, has Holdlonger increase the self life of the chlorine ? Estimate the p-value.