以下是引用azimao在2008-6-9 10:53:00的发言：yes! Definitely I know this method. But the var is .18, why should we use 18? Is that a convention in this case? Never see a cov as huge as 290. If i lose point on this question i would be really pissed off. So pls let me know if it's a convention i missed. | 
发表于 2008-6-14 04:01
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