Yes there will probably be correlations between a large number of your parameters (known as multicollinearity).
The best statistics package that I've personally used is SPSS - might be expensive though (I use the one my university pays for so no idea how much a license costs).
To be honest...
Simple linear regression would be the easiest approach, assuming it is suitable for the data you have. Excel can do this well enough for most purposes. The value you would be looking for is the r^2 (r squared). With simple linear regression this tells you how 'strong' the relationship is between...
Hello all,
I am currently building a model in Excel for predicting domestic water demand on a daily basis. The daily model will be compared to a more accurate model which runs on timesteps of 5 minutes (the latter is data intensive however which is why we are building a daily model as it...
Hi all,
When working out confidence intervals based on population samples are you supposed to always use t-distributions, standard normal (z) distributions, or do you make a choice based on the sample size?
Up until now I've been lucky enough to have large sample sizes (for some work I'm...
Hello All,
I am currently investigating domestic electricity use and whether or not the average (mean) per person use is affected by the number of people living in a household.
I have monitoring data from several hundred households with household occupancies ranging from 1 to 6 people...
I think my main problem is that I only have data for one sample from the population. I was given this data and there's no way we can get any more so I have to deal with this one sample.
From what you were saying it sounds as though confidence intervals don't really apply here - I could work out...
Mmm I am not sure what the point of confidence intervals is then...
In reality, in most circumstances I am only going to have one sample from my population. I can create, say, a 95% confidence interval from this sample but I always thought this meant that there was a 95% chance that the true...
Hello All,
I am having to brush up on my stats for work and it's been a long time (>10yrs) since I've had to even think about this stuff. I could do with some help clarifying a specific point about standard errors and margin of error.
An example I am looking at from my old notes is this: the...
Thanks Statdad, the links look very useful. :)
On a final note - I was originally going to use the numbers 1, 2 and 3 to represent the site pollution levels in the regression analysis. I take it from what I've read so far that this would have been the wrong approach to take, and I would have...
Hi statdad,
Thanks for the reply. Yes I am using the qualitative values as predictors (x-values). From what I've been reading about multiple (linear) regression analysis I will end up with an equation of the form:
y = b1x1 + b2x2 + ...bnxn + c
where b are the coefficients for each x...
Hi All,
Hope this is the right sub-forum for this.
I currently work for an engineering consultancy and am doing some project management what for what are essentially site investigation reports (sites are quite small, typically a few acres/hectares). Our clients are mostly developers who have...