Call:
lm(formula = Y ~ X1 + X2 + X3 + X4 + X5 + X6 + X7 + X8 + X9 + 
    X10 + X11 + X12 + X13 + X14 + X15 + X16 + X17 + X18 + X19 + 
    X20)

Residuals:
     Min       1Q   Median       3Q      Max 
-0.04575 -0.02075  0.00000  0.02075  0.04575 

Coefficients:
            Estimate Std. Error t value Pr(>|t|)    
(Intercept)  0.75575    0.02566  29.453  < 2e-16 ***
X1          -0.19150    0.01120 -17.100 5.38e-13 ***
X2          -0.15000    0.03541  -4.236 0.000447 ***
X3          -0.05000    0.03541  -1.412 0.174144    
X4           0.04000    0.03541   1.130 0.272734    
X5           0.06500    0.03541   1.835 0.082137 .  
X6          -0.14000    0.03541  -3.953 0.000852 ***
X7          -0.08500    0.03541  -2.400 0.026791 *  
X8           0.03000    0.03541   0.847 0.407458    
X9           0.04000    0.03541   1.130 0.272734    
X10         -0.08000    0.03541  -2.259 0.035827 *  
X11          0.08000    0.03541   2.259 0.035827 *  
X12          0.01000    0.03541   0.282 0.780703    
X13         -0.02500    0.03541  -0.706 0.488782    
X14         -0.12000    0.03541  -3.389 0.003083 ** 
X15         -0.05000    0.03541  -1.412 0.174144    
X16         -0.08500    0.03541  -2.400 0.026791 *  
X17         -0.07500    0.03541  -2.118 0.047597 *  
X18         -0.04500    0.03541  -1.271 0.219167    
X19          0.06500    0.03541   1.835 0.082137 .  
X20          0.09000    0.03541   2.541 0.019917 *  
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 

Residual standard error: 0.03541 on 19 degrees of freedom
Multiple R-squared: 0.9605,     Adjusted R-squared: 0.9188 
F-statistic: 23.07 on 20 and 19 DF,  p-value: 2.284e-09 

> anova(allergen.reg)
Analysis of Variance Table

Response: Y
          Df  Sum Sq Mean Sq  F value    Pr(>F)    
X1         1 0.36672 0.36672 292.4238 5.377e-13 ***
X2         1 0.03329 0.03329  26.5459 5.665e-05 ***
X3         1 0.00221 0.00221   1.7637 0.1998955    
X4         1 0.00660 0.00660   5.2640 0.0333368 *  
X5         1 0.01504 0.01504  11.9897 0.0026073 ** 
X6         1 0.02852 0.02852  22.7425 0.0001335 ***
X7         1 0.01001 0.01001   7.9787 0.0108254 *  
X8         1 0.00376 0.00376   2.9988 0.0995321 .  
X9         1 0.00655 0.00655   5.2263 0.0339033 *  
X10        1 0.00796 0.00796   6.3505 0.0208410 *  
X11        1 0.01948 0.01948  15.5308 0.0008769 ***
X12        1 0.00249 0.00249   1.9886 0.1746464    
X13        1 0.00001 0.00001   0.0089 0.9259935    
X14        1 0.01956 0.01956  15.5948 0.0008608 ***
X15        1 0.00298 0.00298   2.3732 0.1399230    
X16        1 0.01411 0.01411  11.2486 0.0033344 ** 
X17        1 0.01681 0.01681  13.4043 0.0016603 ** 
X18        1 0.01402 0.01402  11.1769 0.0034160 ** 
X19        1 0.00053 0.00053   0.4253 0.5221265    
X20        1 0.00810 0.00810   6.4589 0.0199172 *  
Residuals 19 0.02383 0.00125                       
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 
> 
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