Hi, snow!
Supposing you have that data in cells A2:B11 with titles in A1:B1, you can type this formulaes:
For sum: =SUM(B2:B11)
For mode: =MODE.ONE(B2:B11)
About sum I've got no doubt, but about mode... I use Excel 2010 and I don't have any more the function MODE (MODA in spanish), it's been replaced by two functions: MODA.UNO (just one value) or MODA.VARIOS (an array of values). If you have 2010 version, try what I typed; other versions, just try without the ".ONE", that's to say "MODE".
Hope it works.
Regards!