it's not bad

BUT those seem to be sample and not population variances.

There are two cases.

Most people assume the POPULATION variances are equal.

In that case you POOL the twho sample variances.

That would give you a t distribution with 10+10-2 degrees of freedom.

That also looks more like a test statistic, which you can pivot on and slove for the pop means.

Here is the case when you do NOT assume equal pop variances...http://en.wikipedia.org/wiki/Welch's_t_test

Here is the other case