| Source of variance  | 
        Sum of squares  | 
        Degrees of freedom  | 
        Mean square | 
        F value | 
        P value | 
       
      
        | X1  | 
        10.81 | 
        1 | 
        10.81 | 
        0.14 | 
        0.7195 | 
       
      
        | X2  | 
        184.32 | 
        1 | 
        184.32 | 
        2.38 | 
        0.1665 | 
       
      
        | X3  | 
        646.20 | 
        1 | 
        646.20 | 
        8.36 | 
        0.0233 | 
       
      
        | X1X2  | 
        32.49 | 
        1 | 
        32.49 | 
        0.42 | 
        0.5375 | 
       
      
        | X1X3  | 
        18.06 | 
        1 | 
        18.06 | 
        0.23 | 
        0.6436 | 
       
      
        | X2X3  | 
        118.81 | 
        1 | 
        118.81 | 
        1.54 | 
        0.2551 | 
       
      
        | X12  | 
        2359.53 | 
        1 | 
        2359.53 | 
        30.52 | 
        0.0009 | 
       
      
        | X22  | 
        2956.28 | 
        1 | 
        2956.28 | 
        38.23 | 
        0.0005 | 
       
      
        | X32  | 
        719.54 | 
        1 | 
        719.54 | 
        9.31 | 
        0.0186 | 
       
      
        | Model | 
        7685.36 | 
        9 | 
        853.93 | 
        11.04 | 
        0.0023 | 
       
      
        | Residual | 
        541.24 | 
        7 | 
        77.32 | 
          | 
          | 
       
      
        | Pure error | 
        331.65 | 
        4 | 
        82.91 | 
          | 
          | 
       
      
        | Lack of fit | 
        209.59 | 
        3 | 
        69.86 | 
        0.84 | 
        0.5375 | 
       
      
        | Total variation | 
        8226.60 | 
        16 | 
          | 
          | 
          | 
       
      |