The liquid chlorine added to swimming pools to combat algae has a relatively short shelf life before it loses its effectiveness. Records indicate that the mean shelf life of a 4.5 L jug of chlorine is 2160 hours (90 days). As an 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):
2159, 2170, 2180, 2179, 2160, 2167, 2171, 2181, 2185
At the .025 level, has Holdlonger increased the shelf life of the chlorine? Estimate the p-value.