Quote:
Originally Posted by Velvet
Right you are, what is one zero? LOL in my defense hubby was talking continually at me about Formula 1 racing while I was trying to read and write.... So we are talking of Less than 1/2 a percent?
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I am mystified a bit that someone who studied economics doesn't understand the math involved. I'll give you a different example to see if it helps. Take 20,000 who wear seat belts and 20,000 who don't and after 12 months ask "Is there a lower death rate from automobile accidents in the seat belt wearing group?" As very few people in either group are going to have a bad accident in those 12 months your analysis will be of differences in those very few who had a bad accident. Say 10 people die in the no seat belt group but only one in the seat belt wearers. Yes, there are only 11 deaths in the 40,000 people but the power to detect a difference is clearly demonstrated. In this example seat belts are 90% effective in preventing deaths as where 10 died in the non-protected group, only one died in the belt wearers.