To answer this question we will use the following formula for the slope of a line:
[tex]m=\frac{\text{rise}}{\text{run}}\text{.}[/tex]
Since A, B, C, and D are collinear then:
[tex]\text{slope of }\bar{\text{DC}}\text{=slope of }\bar{\text{AB}}\text{.}[/tex]
Now, from the given diagram, we get that, for AB:
[tex]\begin{gathered} \text{rise}=3, \\ \text{run}=4. \end{gathered}[/tex]
Therefore:
[tex]\text{slope of }\bar{\text{AB}}\text{=}\frac{3}{4}\text{.}[/tex]
Answer:
[tex]\frac{3}{4}\text{.}[/tex]
