In the book Design and Analysis of Experiments, 8th edition (2012, John Wiley & Sons), the results of an experiment involving a storage battery used in the launching mechanism of a shoulder-fired ground-to-air missile were presented. Three material types can be used to make the battery plates. The objective is to design a battery that is relatively unaffected by the ambient temperature. The output response from the battery is effective life in hours. Three temperature levels are selected, and a factorial experiment with four replicates is run. The data are as follows:

(a) Test the appropriate hypotheses and draw conclusions using the analysis of variance with α = 0.05.

(b) Graphically analyze the interaction.

(c) Analyze the residuals from this experiment.

Temperature (F) Material Low Medium High 1 130 155 34 40 20 70 74 180 80 75 82 58 150 188 136 122 25 70 45 159 126 106 115 58 138 110 174 120 96 104 150 168 160 139 82 60