confidence-interval

1. Average of standard deviation as repeat accuracy for five measurement series

Hi there, I hope you can help me with the following question. I measured the power input and output of a storage and retrieval vehicle with 1,000 single measuring points. I repeated the measurement five times with the same measure method and same time steps. The result is five measurement series...
2. Minimum P to sample boxes

I have N boxes, each of which may or may not contain a ball. I want to know how many boxes have balls by sampling the boxes in the following way. For each box in the N boxes: I open this box with probability P If at the end I find out K boxes have a ball, I estimate the number of boxes...
3. Negative confidence intervals in regression

Hi all, So I'm really stumped. Basically I have a negative standardised coefficient value of -0.35, and a 95% CI equals (-0.47, -0.23). I'm having trouble interpreting the interval because it's negative. I'd have thought that, the lower and upper bounds would be reversed. Because if the...
4. Confidence interval when data is in range

I am trying to calculate the confidence interval when data is given in range. Example: Rather than telling their exact age in years, 9 sample students from a class tell their age as: (23 +/-1) ; (22 +/-1) ; (20 +/-2 ) ; (25 +/-2) ; (24 +/-2) ; (25 +/-3) ; (22 +/-3) ; (24 +/-4) ; (25 +/-...