Pipe material

1. Pipe index = 0.657119 + 0.0926041 pipe age + 3.66928e−005 pipe

diameter + 0.000892305 pipe depth

2. Pipe index = 0.702251 + 0.0926041 pipe age + 3.66928e−005 pipe

diameter + 0.000892305 pipe depth

Coefficients

Term

Coef

SE Coef

T

P

Constant

0.679685

0.181897

3.7367

0.000

Pipe age

0.092604

0.002947

31.4209

0.000

Pipe diameter

0.000037

0.000954

0.0385

0.969

Pipe material

1

−0.022566

0.035253

−0.6401

0.523

Pipe depth

0.000892

0.000847

1.0538

0.294

Summary of model

S = 0.431973

R-Sq = 86.99%

R-Sq(adj) = 86.64%

PRESS = 29.8366

R-Sq(pred) = 86.13%