Is it possible to process multiple sample sets and get one result?

<p>We have a method that requires the following:</p><p></p><p>Run 10 samples, if the criteria for these 10 samples fails, run 20 more.  We then have to calculate an average using all 30 samples.</p><p></p><p>The problem I see (I haven't tested this yet) is that we will have 2 separate sample sets that we will need to do calculations on.</p><p>Has anyone done this and been able to get results using both sample sets?  If so how do you go about processing and doing the calculations?</p><p></p><p>Thanks,</p><p>Chris</p>