Socioeconomic model of whether Minnesota counties had AP Calculus 2008-2013

This is a first attempt at creating a model using socioeconomic variables and I used those from the decision tree: Population, People per Household, pct Free and Reduced Lunch, Per Capita Income, pct No Father on Birth Certificate, and Population per Square Mile.
Coefficients:
                    Estimate Std. Error z value Pr(>|z|)
(Intercept)                1.837e+01  1.176e+01   1.561   0.1185
data1$pop                6.863e-05  3.416e-05   2.009   0.0445 *
data1$pHouse        -7.694e+00  3.795e+00  -2.027   0.0426 *
data1$pctFreeRed  -8.018e-02  5.991e-02  -1.338   0.1808
data1$PCIncome    -4.612e-05  1.430e-04  -0.323   0.7470
data1$pctNoFather  7.184e-02  6.560e-02   1.095   0.2735
data1$pSQM           3.925e-02  2.581e-02   1.521   0.1282
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Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

As a way to improve on my model, I've made two graphs to show error in the model.