[讨论]请大家探讨一下

25413294 · 发表于 2005-10-21 20:13

若数5经过第一次增长变成数6,再增长一次变成数9,那么在这两个变化过程中,平均增长率是多少?
解法一:设平均增长率为X,有:
　　　 5(1+X)^2=9,则 X≈0.34
解法二:设平均增长率为X,有:
　　　 5+5(1+X)+5(1+X)^2=5+6+9
到底哪一个对呢?
(注“^2”为2次方)[DISABLELBCODE]

semigroup · 发表于 2005-10-23 13:30

第一个吧.

semigroup · 发表于 2005-10-23 13:33

好象不对,应该是(6/5+9/6)/2

digot · 发表于 2005-11-3 18:21

0.2+0.5=0.7
0.7/2=

machi5188 · 发表于 2005-11-3 22:02

还是很难啊，麻烦`！
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林梦启 · 发表于 2005-11-3 22:16

第一个是正确的

wangyangkee · 发表于 2010-5-28 08:01

网络数学家--------俞根强--------的看家本领：
鉴定评估，卖卖烧饼，理值气壮闹蠢货，，，，

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