The lifetime of a tool was investigated under three settings for feed rate and three settings for speed. Four tools were tested under each combination of settings. The results (in hours) were as follows.

a. Construct an ANOVA table. You may give ranges for the P-values.

b. Is the additive model plausible? Provide the value of a test statistic and the P-value.

c. Can the effect of feed rate on lifetime be described by interpreting the main effects of feed rate? If so, interpret the main effects, using multiple comparisons at the 5% level if necessary. If not, explain why not.

d. Can the effect of the speed on lifetime be described by interpreting the main effects of distance? If so, interpret the main effects, using multiple comparisons at the 5% level if necessary. If not, explain why not.

Feed Rate Speed Lifetime Light Light Light Slow 60.6 57.0 61.4 59.7 Medium 57.8 59.4 62.8 58.2 Fast Slow 56.5 52.3 58.1 53.9 Medium 51.2 53.1 48.3 51.6 Medium Medium 49.6 48.1 49.8 51.1 Medium Fast 45.7 48.6 45.0 49.2 Heavy Slow 44.8 46.7 41.9 51.3 eavy Heavy Medium 46.6 41.4 38.3 37.9 Fast 37.2 32.8 39.9 35.9