15.5 In the study An X-Ray Fluorescence Method for Analyzing Polybutadiene-Acrylic Acid (PBAA) Propellants

(Quarterly Reports, RK-TR-62-1, Army Ordnance Missile Command), an experiment was conducted to determine whether or not there was a significant difference in the amount of aluminum obtained in an analysis with certain levels of certain processing variables. The data are shown below.
Phys. Mixing Blade Nitrogen Obs. State Time Speed Condition Aluminum 1 1 1 2 2 16.3 2 1 2 2 2 16.0 3 1 1 1 1 16.2 4 1 2 1 2 16.1 5 1 1 1 2 16.0 6 1 2 1 1 16.0 7 1 2 2 1 15.5 8 1 1 2 1 15.9 9 2 1 2 2 16.7 10 2 2 2 2 16.1 11 2 1 1 1 16.3 12 2 2 1 2 15.8 13 2 1 1 2 15.9 14 2 2 1 1 15.9 15 2 2 2 1 15.6 16 2 1 2 1 15.8 The variables in the data are given as below.
A: mixing time level 1: 2 hours level 2: 4 hours B: blade speed level 1: 36 rpm level 2: 78 rpm C: condition of nitrogen passed over propellant level 1: dry level 2: 72% relative humidity D: physical state of propellant level 1: uncured level 2: cured Assuming all three- and four-factor interactions to be negligible, analyze the data. Use a 0.05 level of significance.
Write a brief report summarizing the findings.