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tango1
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In an experiment the length of a bar is measured many times...normal distribution with mean 1.34 and SD 0.02. Find the prob than any one measured value a) exceeds 1.37 b)is between 1.31 and 1.37 c)is between 1.33 and 1.39 d)find the length h for which the prob that any one measured value is less than h is 0.1.
Thanks in advance to anyone who can do them. I've done abc and just want to check answers but am stuck on d.
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tango1
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please help!
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tango1
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pretty please!!!
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(Original post by tango1)
In an experiment the length of a bar is measured many times...normal distribution with mean 1.34 and SD 0.02. Find the prob than any one measured value a) exceeds 1.37 b)is between 1.31 and 1.37 c)is between 1.33 and 1.39 d)find the length h for which the prob that any one measured value is less than h is 0.1.
Thanks in advance to anyone who can do them. I've done abc and just want to check answers but am stuck on d.

a) z = ( 1.37 - 1.34 ) / 0.02 = 1.5

P = 1 - Phi(1.5) = 1 - 0.9332 = 0.0668

b) Phi (2) - Phi (-2) = Phi (2) - (1-(Phi(2))) = 0.9554

c) Phi (2.5) - Phi (-0.5) = 0.9938 - (1-Phi(0.5)) = 0.9938 - 0.3085 = 0.6853

d) z = x - (x-bar) / SD
Phi^-1 (0.1) = - Phi^-1 (0.1) = -1.2816

=> -1.2816 = ( x - 1.34 ) / 0.02
= -0.025632 = x - 1.34
= 1.314368 = x

Length = 1.314368 units.
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tango1
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Report Thread starter 14 years ago
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thx v.much. good luck on your path towards fame and fortune.(i'm a part time psychic)
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