Seems a bit bleh, but I suppose it might just be examinable but, y'know, not actually going to be asked it in the exam, I haven't really seen 'proofs' in the S3 past papers before.
In the S3 book on page 16, the sum of the quotas in each strata do not add up to the same number, idk if you have the book spare - I will try and upload. Thank you for the reply.
Oh my bad I thought I deleted my comment don't know why it says I wrote a x.
I wrote that x (it's a common letter used to quote someone, you can't leave the quote box empty) and I could not quote your post as you deleted it, but I saw it so.. there
For June 2013 4b. Why do we not take the variance as 6.88/50 rather than just 6.88? I'm sure I'd seen previously that we divide by n even if we estimate the variance. Thanks
For June 2013 4b. Why do we not take the variance as 6.88/50 rather than just 6.88? I'm sure I'd seen previously that we divide by n even if we estimate the variance. Thanks
No? The sample variance is given by ((sum of x^2) - n * (mean)^2)/(n-1) and that's that.
No? The sample variance is given by ((sum of x^2) - n * (mean)^2)/(n-1) and that's that.
So say if in the next part it involved 100 people we would times the probabiltes by 100. So there is no scenario where we'd need to alter the estimated s.d?
Okay say if we were given a normal distribution (we don't need to calculate anything) at the start of q4 would we then divide by 50 I guess as it involves 50 people?