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disjointness
Posted:
Dec 6, 1999 5:31 PM


I'm having difficulty explaining why disjoint events are not independent. YMM states, "If A and B are disjoint, then the fact that A occurs means B cannot occur. So disjoint events are not independent." I'm ok with the first part but I'm having difficulty coming up with an example to show that disjoint events are not independent.
Al Reif wrote <Disjoint events cannot occur simultaneously. When rolling a die, you <could roll a 3 [Event A] or roll a 4 [Event B]. But you cannot roll a 3 and a 4 at the same time with one die. In contrast, rolling a 3 <[EventA] and having blonde hair [Event B] are not disjointthey can happen at the same time.
But isn't rolling a 3 or a 4 on a die independent?
Thanks. Ruth Carver Germantown Academy ======================================================================= The Advanced Placement Statistics List To UNSUBSCRIBE send a message to majordomo@etc.bc.ca containing: unsubscribe apstatl <email address used to subscribe> Discussion archives are at http://forum.swarthmore.edu/epigone/apstatl Problems with the list or your subscription? mailto://jswift@sd70.bc.ca =======================================================================



