Call:
lm(formula = y ~ x)

Residuals:
     Min       1Q   Median       3Q      Max 
-0.03267 -0.02775 -0.01190 -0.00616  0.56592 

Coefficients:
                      Estimate Std. Error t value             Pr(>|t|)    
(Intercept)           0.032667   0.003642   8.968 < 0.0000000000000002 ***
xLow income          -0.021730   0.008199  -2.650             0.008221 ** 
xLower middle income -0.016319   0.006593  -2.475             0.013549 *  
xNA                  -0.021211   0.012561  -1.689             0.091736 .  
xUpper middle income -0.020762   0.006089  -3.410             0.000687 ***
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

Residual standard error: 0.06361 on 707 degrees of freedom
Multiple R-squared:  0.02336,	Adjusted R-squared:  0.01784 
F-statistic: 4.228 on 4 and 707 DF,  p-value: 0.002175