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Show r I I M "rvr ' fnvr'rw'M'vi The art of guessing can be losing battle By Darrell Sifford Knight-Riddc- r Newspaix-r- s If you flip a coin 1,000 times, will you likely get r00 heads and 5(KI tails? Or what about this: The coin youve flipp'd has come up heads loO times in a row. What are the chances that the 101st flip will be tails? Or this: You've driven your car 20 years without an accident. Are your mathematical chances now greater than somebody who just had an accident last week assuming other factors are equal? You think these are tunny questions? Well, dont laugh. At Temple University in Philadelphia, a mathematics professor, Dr. Samuel Kotz, deals seriously with such questions in a course called The Art of Guessing. Kotz, who is associate editor of the Journal of the American Statistical Association, has been at Temple 11 years. In an interview he made these points. A coin flipped 1,000 times isnt likely to produce 500 heads and 500 tails although this is slightly more probable than any of the other 1.000 possible outcomes. Probability is 95 percent that the outcome will be to from 408 heads-tail- s 532 heads-tail- s. In a fair game, Kotz says, if you bet $1 a flip, youd probably win or lose about $30. It is rare that you would break even, Kotz says with a Thats heavy accent. mathematical fiction that everything comes out even if you play long enough. The reality is that youre either ahead a certain amount or behind a certain amount. The odds that a coin would come up heads 100 times in a row are almost too incredible to contemone chance in one plate ; followed by 30 zeroes. ' But if it happened, the odds that the 101st flip would be tails are no tetter than This, Kotz says, is because the odds in games of pure chance includ- - ing roulette and craps have no memory. What that means, he says, is that what happened previously doesnt influence whats going to happen in the future. But what about hot dice. Professor Kotz? If I've rolled five sevens in a row, do 1 have a better or worse chance of rol- - a seven the ting sixth time? Dice are never hot or cold. Thats fiction, too The odds on the sixth roll are exactly the same as the odds on the first roll. But there are games of chance where teds do have memory. Kotz says when you stop flipping coins or rolling dice and begin to play blackjack or other card games in which skill is involvte. Here's the analogy he draws: If 1 have a bag w ith four white balls and three black balls, the odds are four in seven that the first ball I take out will be white. But if you ask me the odds on the second ball before I've picked the first cant answer. That's 1 be- cause the second selection is influenced bv the first. It's the same in blackjack. If I know what's already been played, 1 can compute me probability of my getting what I w ant on my next card." In blackjack the object is to get as close to 21 isiiiils as you can. If you're holding 17 and dont know if you should st anil or ask for another card, you can get a clue. Kotz says, by looking at the cards already turned up on the table. If you see a lot of deuces, threes and fours, then you'd belter stand at 17. Kotz savs, liecause odds are great that the next card you draw will put you ov er 21 and bust you. On the other hand, be says, if mostly high cards are on the table, you have hotter (Kids of getting the low card you need. OK, Professor Kotz, but what about the who wonder if 20 years of safe driving Salt I.akp Tribimp, Sunday, March i.l increase the odds of their having a traffic accident' Don't sweat it. Kotz savs. He assumes that the law governing distribution of auto accidents is without memory it's just like flipping a eoin or rolling the diee and, if every Hung else is equal, sonv'htey who's never had an accident isn't statistically more likely to have one the w 5, 1978 HIS next time out than any body else. Kotz puts it this way: The probability of your having an aeeident on your next trip is the same as the probability on your pre ious trip. But the probability that you eventually will have an accident is great. And it has nothing to do with our or lack driving ability of it. it's just the law of probability at work. Jantzerf.... brings you Stretch Abouts, separates that were made with your lifestyle movement w ith maximum combine in mind. They the minimum care of Visa, Millikens unique polyester fabric. (See our Visa demonstration in all our stores during Visa Week). 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Times News Service If NEW YORK youre already fed up with Mickey Mouse, Teddy Bear and Barbie doll, this could be a hard year. Each of those toys is celebrating an anniversary: Teddy will be 75, Mickey 50, the fashion-mad Barbie has teen adding clothes to her collection for 20 years now. And at the Toy Manof America's a good annual fair forecaster of the toys that will be sold most ufacturers energetically next fall it was clear that the manufacturers about to ignore arent those anniversaries and hoping the millions of fans of those characters wont either. The teddy bear is an updated version of the original named for Theodore Roosevelt and made then, as now, by Ideal Toys. Among the new Mickey Mouse toys will be everything from Birthday Party Mickey, a squeeze toy which enables Mickey to blow a party favor, a horn, a balloon or bubbles, to an theyre eight- digit Mickey Mouse calculator (Mickey makes math more fun!). 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