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, 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):
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.

(a) State the null hypothesis and the alternate hypothesis.

(b) State the decision rule for .025 significance level.

(c) Compute the value of the test statistic

(d) At the .025 level, has Holdlonger increased the shelf life of the chlorine?

(e) Estimate the p-value.