Independent variables. The equation of the fitted model is

C = 0,714703*Y - 2,72156*Irr - 0,348232*G

Since the P-value in the ANOVA table is less than 0.01, there is a

statistically significant relationship between the variables at the

99% Confidence level.

The R-Squared statistic indicates that the model as fitted

explains 99,9682% of the variability in C. The adjusted R-squared

statistic, which is more suitable for comparing models with different

numbers of independent variables, is 99,9659%. (Note: since the model

does not contain a constant, you should be careful in interpreting the

R-Squared values. Do not compare these R-Squared values with those of

models which do contain a constant.) The standard error of the

estimate shows the standard deviation of the residuals to be 42,9585.

This value can be used to construct prediction limits for new

observations by selecting the Reports option from the text menu. The

mean absolute error (MAE) of 34,2434 is the average value of the

residuals. The Durbin-Watson (DW) statistic tests the residuals to

determine if there is any significant correlation based on the order

in which they occur in your data file. Since the DW value is greater

than 1.4, there is probably not any serious autocorrelation in the

residuals.

In determining whether the model can be simplified, notice that the

highest P-value on the independent variables is 0,1500, belonging to

Irr. Since the P-value is greater or equal to 0.10, that term is not

statistically significant at the 90% or higher confidence level.

Consequently, you should consider removing Irr from the model.

Multiple Regression Analysis W.1

-----------------------------------------------------------------------------

Dependent variable: W

-----------------------------------------------------------------------------

Standard T

Parameter Estimate Error Statistic P-Value

-----------------------------------------------------------------------------

CONSTANT 13,4472 0,629365 21,3663 0,0000

P 0,0176211 0,00214707 8,20703 0,0000

Ur -21,7858 9,55095 -2,28101 0,0307

-----------------------------------------------------------------------------

Analysis of Variance

-----------------------------------------------------------------------------

Source Sum of Squares Df Mean Square F-Ratio P-Value

-----------------------------------------------------------------------------

Model 21,4052 2 10,7026 51,01 0,0000

Residual 5,66529 27 0,209826

-----------------------------------------------------------------------------

Total (Corr.) 27,0705 29

R-squared = 79,0721 percent

R-squared (adjusted for d.f.) = 77,5219 percent

Standard Error of Est. = 0,458067

Mean absolute error = 0,338887

Durbin-Watson statistic = 0,499488

The StatAdvisor

---------------

The output shows the results of fitting a multiple linear

regression model to describe the relationship between W and 2