I think you find the percentage errors in each case and then just add them up.

But I'm only answering because no one clever had come along yet. 

If you can understand this - http://www.rod.beavon.clara.net/err_comb.htm - it might help. 

I'm no scientist but I think that's the right way. I would take the difference between the expected result for concentration and the actual result, then divide that by the expected result and show that as a percentage. Repeat this for the burette results and the volumetric flask results.

Add the three percentages together (but if any of the results are negative still add it rather than deduct it).

I have no idea what you even said.

So - no i don't

*sits next to Baz and Saint*

  <------ me looking confused but I agree with Blizz (mainly because she scares me) 

BOO!! 

  <---- open mouthed scared now 

I wouldn't expect her to come back in here to discuss Chemistry anytime soon..   she's just put up a status on FB saying she is off out on the lash dressed as a Teenage Mutant Ninja Turtle 

Hmmm, should we calculate the error in that? 

Don't know your exact application Ickle ..nor if this helps but...

Google is your friend!!!!

http://www.rod.beavon.clara.net/err_comb.htm

Z.

Budge up. I'm with you peeps.

Wrong forum 

Well hello there stranger.  

Hope all is well and Rufus is barking healthily too.   Nice to see you.

OMG! wuz that her......whoosh! she was fast! 

Ermmm 

Do you know what she is on about....

Mine hed hurtz

All is well Cinds.. Rufus too.. you?

Z.

I read the OP and was like 

I read it again and thought .............I didn't know Ickle was doing hairdressing. I read burette as brunette - thought she'd made an error colouring someones hair.

I'm not very scientific  What's more I'm TT now so there really was no excuse