Hi,
My stats is rusty. I have some sales data and I want to show what customers are past the fist standard deviation in spending with us. The data is strucutred like this:
| Account | Sale |
| A | 10 |
| B | 20 |
| A | 50 |
| A | 10 |
| C | 80 |
| B | 5 |
I can put this in a matrix with account in rows and sales in values and it gives me a nice summary of the accounts and total sales. What I want to do it caculate the standard deviation of this and then display those accounts that are past the fist stdev. How can I calculate the standard deviation of total account spending?
My stats is Very rusty... if this was a normal distribution then can I just say that the percentage past the 1st stdev is 16.9% (50-34.1) and therefore I can just take the top 16.9% of my data?
Any help here greatly appreicated.
Best,
Nick
