Sample size question - Help!
Message posted by Steven on November 20, 2000 at 12:00 AM (ET)

I am supporting a study that has to do with safety. One of the databases is very large, so large in fact, it will be impossible to read all the records.

The database consists of 205,070 records. Initially, a random sample of 4,458 records was generated, and of this amount, 133 have been analyzed. Due to the narrative manner of each record, the going is pretty slow.

Can you help me with the following questions?

1. To what degree does 133 randomly selected records represent the total population?
2. What is the appropriate size of a random sample (with a small margin of error and a high confidence level 95% for example), that it represents the population of 205,070?
3. What is the formula or procedure for calculating sample sizes and degree of certainty?

I hope the questions are written sufficiently clear. If I have not supplied all the necessary information, or if the questions are not clear, please contact me.

In advance, thank you very much for your help. smccann@qedllc.com