An article published in Engineering Structures and Technologies (Sept. 2012) presented the results of a study on the use of processed straw as thermal insulation for homes. Chopped straw specimens were prepared and tested for thermal conductivity at a temperature of 10° Celsius. Two variables were measured for each of 25 straw specimens:
y = thermal conductivity (watts per meter-Kelvin) and
x = density (kilograms per cubic meter). The data are provided in the accompanying table. Consider the quadratic model E(y) = β0 + β1x + β0x2. Conduct a complete analysis (including a residual analysis) of this model. Summarize your results in a report.

Thermal Specimen Conductivity (y) Density (x) 1 2 3 4 0.052 0.045 0.055 49 50 51 56 57 0.042 0.048 6. 0.049 0.046 0.047 0.051 0.047 62 64 65 66 68 8. 10 11 12 13 14 15 16 17 0.049 0.048 0.048 0.052 0.051 0.053 78 79 82 83 84 98 100 100 101 103 115 116 0.054 0.055 0.057 0.055 0.074 18 19 20 21 22 0.075 0.077 0.076 0.074 23 24 25 118 119 120