Triangle $DEF$ is shown.  What is $\cos{E}$?

[asy]
draw((0,0)--(7,0)--(7,24)--cycle,black+linewidth(1));
draw(rightanglemark((0,0),(7,0),(7,24),30),black+linewidth(1));
label("$E$",(7,24),E);
label("$F$",(0,0),W);
label("$D$",(7,0),E);
label("7",(0,0)--(7,0),S);
label("24",(7,0)--(7,24),E);
[/asy]
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Triangle $DEF$ is shown.  What is $\cos{E}$?

[asy]
draw((0,0)--(7,0)--(7,24)--cycle,black+linewidth(1));
draw(rightanglemark((0,0),(7,0),(7,24),30),black+linewidth(1));
label("$E$",(7,24),E);
label("$F$",(0,0),W);
label("$D$",(7,0),E);
label("7",(0,0)--(7,0),S);
label("24",(7,0)--(7,24),E);
[/asy]
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
\frac{24}{25}
Triangle $DEF$ is shown.  What is $\cos{E}$?

[asy]
draw((0,0)--(7,0)--(7,24)--cycle,black+linewidth(1));
draw(rightanglemark((0,0),(7,0),(7,24),30),black+linewidth(1));
label("$E$",(7,24),E);
label("$F$",(0,0),W);
label("$D$",(7,0),E);
label("7",(0,0)--(7,0),S);
label("24",(7,0)--(7,24),E);
[/asy]
train