Estimate the p-value

18. 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 5-gallon jug of chlorine is 2,160 hours (90 days). As an experiment, Hold longer 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): 2,159 2,170 2,180 2,179 2,160 2,167 2,171 2,181 2,185

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