I have couple questions about this and I was hoping someone with some stats knowledge could clarify. First, when people report numbers such as 10 plus or minus 5, what does the 5 mean? Is it the standard deviation or the confidence interval or the variance? What is the relationship between all these terms? Secondly, when a linear regression is found on excel (or some other software) and the standard error of the slope and intercept are calculated, how do I get from this value to the plus or minus value used above. Basically, what I'm asking is how is standard error related to the standard deviation, confidence interval, or plus or minus values? Also, how do I use the propagation of error equations? What do I use for the uncertainty in each variable? There is a lot of jargon here that I don't really understand, can someone clarify?