# standard deviation

1. ### statistics applied to flow

Hi there, I have been trying to solve the problem below, but have had difficulties in solving it. I would really appreciate it if anyone could explain to me how to solve it. The standard deviation of the flow is s=0.3 occuring where the mean concentration is 0.9. The mean concentration is...
2. ### Impulse Response Functions

I have obtained point estimates for impulse response functions. How can I tell if it's values are significant?
3. ### multiplying Standard error of means

Hi guys, I am new here (and also to statistics :o). I have a data set of many measurements. For each one of them I calculated the mean and the SD (deviation). From that I calculated separately for each of the data set a SEM. Now I would like to multiply, divide add and subtract this data...
4. ### Normal Distribution & possible Standard Deviation error

I have collected final sales data for over 12,000 sales of a single particular item. The prices range from $0.01 to a little over$4.00. I calculate a mean of $0.60. My problem is my standard deviation is$0.58. That doesn't make sense to me. If I move 2sd to the left I am at a negative number...
5. ### "averaging" standard deviations

Hello, I've been given the mean and standard deviation of many sets of the same measurement (bead size). So, I basically have a list of means and a list of corresponding standard deviations. I need to pool and analyze the data to figure out the overall distribution of bead size over these...
6. ### Difference between standard deviation and standard error

Hi, what exactly is the difference between the SD and SE? I read through the wikipedia article but dont really understand the difference. Can anyone help? Cheers beginner