Propagation of Uncertainties
None of your methods are correct. If you have a small data set - in this case, 5 values from a titration - then the absolute uncertainty for each individual value is half the range of data. For example, say you get the following results (in ml, from a burette with a precision of 0.05ml): $4.70$, $5.35$, $4.85$, $4.60$ and $5.20$. The range of these results is $5.35-4.60=0.75$. This gives an absolute uncertainty of $\frac{0.75}{2}=0.375$ for each individual piece of data e.g. $4.85\pm0.38$ml. 

However, if the absolute uncertainty calculated from half the range is less than the precision of the instrument (in this case $&lt;0.05$ ), then the precision of the instrument should be given as the uncertainty e.g. $5.00\pm0.05$. I think you may have incorrectly calculated the absolute uncertainties.

For small data sets ($&lt;10$ pieces of data), the uncertainty in the mean is then given by $$\Delta {x}_{avg}=\frac{\Delta x}{\sqrt{N}}=\frac{R}{2\sqrt{N}}$$ where $\Delta {x}_{avg}$ is the uncertainty in the mean, ${N}$ is the number of times the measurement was repeated, $R$ is the range and $\Delta{x}$ is the uncertainty in one measurement.

For example, using the example data above, $\Delta {x}_{avg}=\frac{0.375}{\sqrt{5}}=0.168$. The average can then be stated as $4.94\pm0.17$ml