Problem 12.5 The data in the following table are the results of a test in which the burst strengths of cardboard boxes made with four different types of wood pulp were studied; three measurements were taken for each wood pulp mixture. Wood pulp Burst strength (psi) 1 237 219 209 2 205 202 201 3 144 220 167 4 256 246 245

(a) Compute the four treatment means and the grand mean (y1.,... y4., y..).

(b) Compute SSTr, SSE, and SST.

(c) Construct the ANOVA table and test at the level α = 0.05 whether the four types of boxes have the same mean burst strength.