A particular county employs three assessors who are responsible for determining the value of residential property in the county. To see whether these assessors differ systematically in their assessments, 5 houses are selected, and each assessor is asked to determine the market value of each house. With factor A denoting assessors (I = 3) and factor B denoting houses (J = 5), suppose SSA = 11.7, SSB = 113.5, and SSE = 25.6.
a. Test H0: α1 = α2 = α3 = 0 at level .05. (H0 states that there are no systematic differences among assessors.)
b. Explain why a randomized block experiment with only 5 houses was used rather than a one-way ANOVA experiment involving a total of 15 different houses, with each assessor asked to assess 5 different houses (a different group of 5 for each assessor)?