To find the correct result of Hiroshi's multiplication, we need to multiply \( \frac{2}{7} \) by \( 3 \).
The multiplication can be performed as follows:
\[ \frac{2}{7} \times 3 = \frac{2 \times 3}{7} = \frac{6}{7} \]
So, the final answer Hiroshi should have gotten is \( \frac{6}{7} \).