$\,MA\,=\,\dfrac{\frac{3}{5}\,+\,\frac{13}{4}\,+\,\frac{1}{2}}{3}\,=\,$
$\,=\dfrac{\frac{12\,+\,65\,+\,10}{20}}{3}\,=\,\dfrac{\frac{87}{20}}{3}\,=\,\dfrac{87}{20}\times \dfrac{1}{3}\,=\,\dfrac{29}{20}$

resposta: A média aritmética é $\;\dfrac{29}{20}$.