Question: Different rounding with evalf

Why do I get different results for these four command? BTW only Result #2 is correct.

> evalf((1/2)*sqrt(3.0), 5);
                            0.86605
> evalf((1/1)*sqrt(3.0*(1/4)), 5);
                            0.86603
> evalf((1/1)*sqrt(3/4), 5);
                            0.86605

> evalf((1/2)*sqrt(3), 5);
                            0.86605

I have read the answer to a similar question, 

which says that evalf ist doing all the intermediate computation with (in this case) 5 digits.

But even then statement 2 and 3 should produce the same output, which isn't he case.

Ins't the evalf command applied to 3/4 as well as to 3.0/4? Or is here Maple automatically 
rewriting sqrt(3/4) in 1/2*sqrt(3) before applying any evalf?

What would be the right command to get an accurate rounded result for

1/2)*sqrt(3)?

Does anybody know the answers?