HW2_2006

# HW2_2006 - 2-40 a The correlation coefficient will be...

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2-40. a) The correlation coefficient will be positive 240 230 220 210 200 190 180 170 160 150 140 170 160 150 140 130 120 systolic BP weight b) 0.773 2-42. a) 6 001 , 62 433 , 10 2 6 1 6 1 2 = = = = = n x x i i i i Ω = Ω = Ω = = = = = 46 . 4 9 . 19 9 . 19 1 6 6 001 , 62 433 , 10 1 2 2 2 6 1 6 1 2 2 s n n x x s i i i i b) 6 5 . 41 6 246 = = = n x () Ω = Ω = Ω = = = = 46 . 4 9 . 19 ; 9 . 19 5 5 . 99 1 2 2 6 1 2 2 s n x x s i i c) Ω = Ω = 46 . 4 9 . 19 2 2 s s ; Shifting the data from the sample by a constant amount has no effect on the sample variance or standard deviation. d) Yes, the rescaling is by a factor of 10. Therefore, s 2 and s would be rescaled by multiplying s 2 by 10 2 (resulting in 1990 Ω 2 ) and s by 10 (44.6 Ω ).

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3-13. a) P(X 7000) = 1 – P(X > 7000) = 1 – 0.45 = 0.55 b) P(X > 5000) = 1 – P(X 5000) = 1 – 0.05 = 0.95 c) P(5000 < X 7000) = P(X 7000) – P(X 5000) = 0.55 – 0.05 = 0.50 3-27. a) P(X < 209) = 0.1(209) – 20 = 0.9 b) P(200 < X < 208) = F(208) – F(200) = 0.8 – 0 = 0.8 c) P(X > 209) = 1 – F(209) = 1 – 0.9 = 0.1 d) f(x) = 0.1 for 200 x 210 e) 210 205 200 0.105 0.100 0.095 x f(x) 210 205 200 1.0 0.5 0.0 x F(x)
f) E(X) = 205, V(X) = 8.3333 3-41 . a) P(90.3 < X) = < Z 1 . 0

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## This note was uploaded on 02/27/2008 for the course CHE 405 taught by Professor Shing during the Spring '06 term at USC.

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HW2_2006 - 2-40 a The correlation coefficient will be...

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