There is a formula for finding distances using coordinates:
[tex] d=\sqrt{(x_{2}- x_{1})^{2} + (y_{2}-y_{1})^{2} }[/tex]
Inserting your variables:
[tex]d=\sqrt{(4- 3)^{2} + (7-4)^{2} }[/tex]
[tex]d=\sqrt{(1 + 9)}[/tex]
[tex]d=\sqrt{10}[/tex]
The answer is [tex] \sqrt{10} [/tex]