The Following Frequency Distribution Shows the GMAT Scores of a Sample

The following frequency distribution shows the GMAT scores of a sample of MBA students:
$\begin{array}{lc}\text { GMAT Score }&\text { Frequency }\\300 \mathrm{up} \text { to } 400 & 2 \\400 \mathrm{up} \text { to } 500 & 6 \\500 \mathrm{up} \text { to } 600 & 10 \\600 \mathrm{up} \text { to } 700 & 5 \\700 \mathrm{up} \text { to } 800 & 2\end{array}$ For the above data, compute the mean GMAT score.