Since s2\= $$\frac {1}{4}$$（3.2- $$\bar{x}$$）2+（5.7- $$\bar{x}$$）2+（4.3- $$\bar{x}$$）2+（6.8-$$\bar{x}$$）2,

We know that $$\bar{x}$$ is the mean of 3.2, 5.7, 4.3, and 6.8.

Therefore, $$\bar{x}$$ = (3.2 + 5.7 + 4.3 + 6.8) ÷ 4

= 20 ÷ 4

= 5

So the answer is: \boxed{5}.

The variance of a set of data is the average of the squared differences from the mean, so $$\bar{x}$$ is the mean of 3.2, 5.7, 4.3, and 6.8. By calculating the mean, we find the value of $$\bar{x}$$.

This problem primarily tests the understanding and calculation of variance. It is essential to master the concept that the variance is the average of the squared differences from the mean.