35. The number of miles of useful tread wear (in 1000 s)

was determined for tires of each of ve different makes of subcompact car (factor A, with I  5) in combination with each of four different brands of radial tires (factor B, with J  4), resulting in IJ  20 observations. The values SSA  30.6, SSB  44.1, and SSE  59.2 were then computed. Assume that an additive model is appropriate.

a. Test H0: a1  a2  a3  a4  a5  0 (no differences in true average tire lifetime due to makes of cars) versus Ha: at least one ai  0 using a level .05 test.

b. H0: b1b2b3b40 (no differences in true average tire lifetime due to brands of tires) versus Ha: at least one bj  0 using a level .05 test.