mont4e_sm_ch05_sec05

# Then e x 10 and v x 01 a p 9 x 11 p

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Unformatted text preview: Z < ⎜ Then 12 −12.1 σ / 100 ⎝ = -2.58 and σ = 0.388 . 12 − 12.1 ⎞ ⎟ = 0.005. ⎟ σ / 100 ⎠ ⎛ 12 − 12.1 ⎞ ⎟ = 0.01. ⎟ 0.5 / n ⎠ ⎝ = -2.33 and n = 135.72 ≅ 136 . e) P( X < 12) = 0.01 implies that P⎜ Z < ⎜ Then 5-63 12 −12.1 0.5 / n Let X denote the average thickness of 10 wafers. Then, E( X ) = 10 and V( X ) = 0.1. a) P (9 < X < 11) = P ( 9 −10 < Z < 11−10 ) = P(−3.16 < Z < 3.16) = 0.998 . 0.1 0.1 The answer is 1 − 0.998 = 0.002 b) P ( X > 11) = 0.01 and σ X = Therefore, P( X > 11) = P( Z > 1 n 11−10 1 n . ) = 0.01 , 11 − 10 1 = 2.33 and n = 5.43 which is n rounded up to 6. c) P ( X > 11) = 0.0005 and σ X = σ Therefore, P( X > 11) = P( Z > 11−10 σ 10 . ) = 0.0005 , 10 11−10 σ = 3.29 10 σ = 10 /...
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## This document was uploaded on 02/09/2014.

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