1. 請問c 是多少?
P(c <= |Z| )= 0.016
為什麼答案是 2.41
這不是說 c<= -Z and c<=Z 就代表c<=Z ??
我想不出來怎麼會是2.41
查表 Z值2.41是0.9920
2.Suppose the force acting on a column that helps to support a building
is normally distributed with mean 15.0 kips and standard deviation 1.25
kips.
What is the probability that the force:
b. Is between 10 and 12 kips? ans:0.0082
這題是不是 說P (12-15/1.25 <= Z <= 10-15/1.25)
12-15 /12.5 = -2.4 查表得 0.207
可是 10-15/1.25 = -4 Z表裡面查不到-4勒@@?
請問我哪裡錯了???
c.differ from 15.0 kips by at most 1.5 standard deviations?
這什麼意思，是說把 standard deviations改成1.5 重算一次嗎 ?
謝謝
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