> sg.mod1 <- lm(sqrtA[cartridge==2] ~ range[cartridge==2])
> summary(sg.mod1)

Call:
lm(formula = sqrtA[cartridge == 2] ~ range[cartridge == 2])

Residuals:
    Min      1Q  Median      3Q     Max 
-3.3760 -1.0322  0.1133  0.6462  4.9540 

Coefficients:
                      Estimate Std. Error t value Pr(>|t|)    
(Intercept)            0.01267    0.75413   0.017    0.987    
range[cartridge == 2]  0.30327    0.02274  13.337 1.18e-13 ***
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 

Residual standard error: 1.761 on 28 degrees of freedom
Multiple R-squared: 0.864,      Adjusted R-squared: 0.8591 
F-statistic: 177.9 on 1 and 28 DF,  p-value: 1.184e-13 

> anova(sg.mod1)
Analysis of Variance Table

Response: sqrtA[cartridge == 2]
                      Df Sum Sq Mean Sq F value    Pr(>F)    
range[cartridge == 2]  1 551.82  551.82  177.89 1.184e-13 ***
Residuals             28  86.86    3.10                      
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 
> 
> sg.mod2 <- lm(sqrtA[cartridge==2] ~ range[cartridge==2], 
+   weight=regweight[cartridge==2])
> summary(sg.mod2)

Call:
lm(formula = sqrtA[cartridge == 2] ~ range[cartridge == 2], weights = regweight[cartridge == 
    2])

Residuals:
     Min       1Q   Median       3Q      Max 
-1.89497 -0.64274  0.06264  0.42523  1.85880 

Coefficients:
                      Estimate Std. Error t value Pr(>|t|)    
(Intercept)             0.3821     0.2940   1.299    0.204    
range[cartridge == 2]   0.2923     0.0166  17.604   <2e-16 ***
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 

Residual standard error: 1.035 on 28 degrees of freedom
Multiple R-squared: 0.9171,     Adjusted R-squared: 0.9142 
F-statistic: 309.9 on 1 and 28 DF,  p-value: < 2.2e-16 

> anova(sg.mod2)
Analysis of Variance Table

Response: sqrtA[cartridge == 2]
                      Df Sum Sq Mean Sq F value    Pr(>F)    
range[cartridge == 2]  1 332.06  332.06  309.89 < 2.2e-16 ***
Residuals             28  30.00    1.07                      
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1