Yahoo Answers: Answers and Comments for Standard normal distrubition [數學]
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From Anonymous
enUS
Wed, 01 Jan 2014 13:08:33 +0000
3
Yahoo Answers: Answers and Comments for Standard normal distrubition [數學]
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https://answers.yahoo.com/question/index?qid=20140101000051KK00064
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From 知足常樂: X ~ N(42.2, 3²)
Pr( 41.2 < X < 46.3)
...
https://answers.yahoo.com/question/index?qid=20140101000051KK00064
https://answers.yahoo.com/question/index?qid=20140101000051KK00064
Wed, 01 Jan 2014 13:18:53 +0000
X ~ N(42.2, 3²)
Pr( 41.2 < X < 46.3)
= Pr( 41.2  42.2 < X  42.2 < 46.3  42.2 )
= Pr( (41.2  42.2)/3 < (X  42.2)/3 < (46.3  42.2)/3 )
= Pr( 1/3 < (X  42.2)/3 < 4.1/3 )
= Pr( 1/3 < Z < 4.1/3 ) where Z ~ N(0, 1)
= Pr( 0.333333333 < Z < 1.36666666 )
≈ Pr( 0.33 < Z < 1.37 )
= Pr( 0 < Z < 1.37 ) + Pr( 0 < Z < 0.33 )
= 0.4147 + 0.1293 [from standard normal distribution table]
= 0.544
Excel gives you a more accurate answer as 0.544693755.
=NORM.DIST(46.3,42.2,3,TRUE)NORM.DIST(41.2,42.2,3,TRUE)