【求助】一道fair coin的数学题

农夫swamp · 发表于 2012-9-9 16:33:38

A fair coin is tossed 100 times and the number
of heads is recorded. If this experiment is
repeated many times, the number of heads will
form an approximately normal distribution with
a mean of 50 and a standard deviation of 5.
a . Within what limits should we expect the
number of heads in 100 tosses to lie?
b . What is the probability that heads will
occur fewer than 45 times in 100 tosses?

农夫swamp · 发表于 2012-9-9 16:43:07

不要沉……

LF928 · 发表于 2012-9-9 19:13:44

你确定这是GMAT数学题？

农夫swamp · 发表于 2012-9-9 22:51:12

网上的例题什么的

农夫swamp · 发表于 2012-9-10 19:09:47

zhaokejack · 发表于 2012-9-10 19:55:54

我觉得是：
1.35-65
2.16percent

农夫swamp · 发表于 2012-9-10 23:44:28

( ⊙ o ⊙ )是的！！！！！！！！！！！！
求原因！！！！！！！！！1

农夫swamp · 发表于 2012-9-11 09:39:39

【求助】一道fair coin的数学题

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