I am having a problem using the StDev function in Crystal 8.0. I am trying to determing the mean and stdev of lab values for specimens. The mean comes out fine, but the stdev comes out far above what is expected. However, when I run the report for a smaller number of samples, it comes out correctly. And, if I run the report several times, using smaller groups for all the specimens, it comes out correct. Does crystal have a limit to the number of records it can calculate the stdev on? The number of specimen records being used is close to 100,000.
To further explain my problem, I just ran a report calculating the mean and standard deviation of test results for about 120,000 specimens. When I ran the report for all the specimens at once, I got a mean of ~14.5 and a standard deviation of ~40. I reran the report using the specimens one month at a time, and came out with means of ~14 and the standard deviation dropped to 9-10. Does crystal have a limit to the number of records it can handle?
Thanks
To further explain my problem, I just ran a report calculating the mean and standard deviation of test results for about 120,000 specimens. When I ran the report for all the specimens at once, I got a mean of ~14.5 and a standard deviation of ~40. I reran the report using the specimens one month at a time, and came out with means of ~14 and the standard deviation dropped to 9-10. Does crystal have a limit to the number of records it can handle?
Thanks