43. The article “Statistical Design and Analysis of Qualification Test Program for a Small Rocket Engine” (Industrial Quality Control, 1964: 14–18) presents data from an experiment to assess the effects of vibration (A), temperature cycling (B), altitude cycling (C), and temperature for altitude cycling and firing (D) on thrust duration. A subset of the data is given here. (In the article, there were four levels of D rather than just two.) Use the Yates method to obtain sums of squares and the ANOVA table. Then assume that three- and four-factor interactions are absent, pool the corresponding sums of squares to obtain an estimate of 2

, and test all appropriate hypotheses at level .05.

D1 D2

| C1 C2 C1 C2 A1 B1 | 21.60 21.60 11.54 11.50 B2 | 21.09 22.17 11.14 11.32 A2 B1 | 21.60 21.86 11.75 9.82 B2 | 19.57 21.85 11.69 11.18