Answer:
[tex] CD \approx5.29[/tex]
Step-by-step explanation:
By geometric mean theorem:
[tex]CD=\sqrt {AD\times BD} \\ \\ CD=\sqrt {7\times 4} \\ \\ CD=\sqrt {28} \\ \\ CD=5.29150262 \\ \\ CD \approx5.29[/tex]
