Recent content by DaanV

Thank you @FactChecker for your reply. :) I am aware I should not simply be using the ratio of the individual variances. As you point out, this would make little sense. And it would lead to enormous issues if σR is (very) small. My question is whether there is some accepted method of taking...

Thanks a lot @Stephen Tashi . This is very useful. I'll see if I can get you meaningful answers and will try to be more precise in my terminology. Right. I was hoping for it to be less ambiguous. I was hoping that there was some consensus on how to treat sample variance of a ratio of two...

Sorry for inclarity. The 0.5% was supposed to be the rough error for pipetting 9μl -- we'd generally be pipetting 9.0 μl ± 0.05 μl. Actually the total reaction volume (after adding all reagents necessary to get the PCR running) is 20 μl, so your initial reasoning is sort of valid: 20 μl at...

Thank you again Jim and BvU for your insights and continued interest. I am aware of significant digits. I follow the number of significant digits that the software reports, which I assume to be relevant and meaningful. Again, the above data was purely fictional. I am unsure how much detail...

Thanks a lot BvU for taking the time to help me out. It is really appreciated. I am happy to hear my additional explanation helped. I will look into whether there are situations imaginable where there is great difference between the two approaches mentioned. I will surely look closer into...

Thank you jim mcnamara and BvU for your replies. I am sorry for any confusion caused by my poor description. Please allow me to rephrase, plus give a bit more detail on the experimental setup. I hope that helps clearing up any confusion at all. This problem stems from oncology/genetics. The...

This is from labwork experiments. I have no background in mathematics. We have an experimental setup that measures the levels of two targets: The Reference (R) and the target of Interest (I). We are interested in the ratio I/R. For healthy individuals we know this ratio to be precisely 1. For...

Thanks for all the replies guys. Only just now checking back after the weekend. For now, I do think it would be sufficient to show whether or not the events (Red and/or Green) are independent. I will look up chi square test for independence (sorry, as noted I'm not a statistics guy). Terribly...

Since you ask.. This is a problem derived from my research in a cancer institute. Have you ever heard of (Droplet) Digital PCR? In essence, the idea is to dilute a sample containing DNA to limiting dilutions, until you reach a point where you would only expect one DNA molecule of interest in a...

You're absolutely right. Sorry about the confusion. That's right, I don't know ##N_A## and ##N_B## (the numbers of green and blue balls). I only know the number of buckets that have balls in them, and what colour(s) are in those buckets. I am indeed trying to test whether or not the balls are...

Homework Statement I have run into a situation that my gut tells me is impossible (alright extremely unlikely) when assuming a Poisson distribution. I want to make this gut feeling more formal by testing it against a Poisson distribution. Sadly I'm not a schooled statistician. Generalised...

Thread revival! So I’ve been mulling this one over a bit more. I have come to the conclusion that the previous answer, although correct, actually wasn’t what I was looking for. The requirement of X% odds of having zero duplicates is too stringent for my application. So please allow me to...

Sorry, yes, I do suppose I meant that. More completely: "I am giving each component a randomly chosen identifier. I would like to give each component a unique identifier. How can I determine the number of unique identifiers N, so that I have at least 99% odds of having no duplicate...

Well.. That just goes to show I should probably dive into Wikipedia first next time. :) Thanks for your help, that solved it perfectly.

Mod note: Removed "Basic calculus" from thread title, as the question doesn't seem to have anything to do with calculus Homework Statement Real world kind of thing. Assume I have a set of C components that I want to investigate. I want to give each component a unique identifier. I have N...