To compare lumen output of 3 different brands of light bulbs, 8 light bulbs of each brand were randomly selected and tested. The sums of squares were computed as SSTr = 591.2, SST =5364.5.
(a) State the null and alternative hypotheses for the ANOVA (include definitions of parameters). What assumptions do we need to proceed with ANOVA?
(b) Fill out the ANOVA table for this problem and carry out the test of the null hypothesis at level α = 0.05. State you conclusion.
(c) How would the conclusion of (b) be affected if the sample sizes were 4 instead of 8? Answer without doing calculations, and explain.