409Quiz5Cans - p XA = p YA p XB = p YB p XAB = p YAB E 11 = 500 230 300 × = 138 E 12 = 500 120 300 × = 72 E 13 = 500 100 300 × = 60 E 14 = × =

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STAT 409 Fall 2011 Name ANSWERS . Version C Quiz 5 (10 points) Be sure to show all your work, your partial credit might depend on it. No credit will be given without supporting work. 1. We wish to test whether the proportions of individuals with each of the four blood types are the same in two neighboring towns, Town X and Town Y. A random sample of 300 individuals from Town X and 200 individuals from Town Y produced the following observed frequencies: Blood Type O A B AB Town X 130 75 70 25 300 Town Y 100 45 30 25 200 230 120 100 50 500 Use α = 0.10 to test H 0 : p XO = p YO ,
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Unformatted text preview: p XA = p YA , p XB = p YB , p XAB = p YAB . E 11 = 500 230 300 × = 138 E 12 = 500 120 300 × = 72 E 13 = 500 100 300 × = 60 E 14 = 500 50 300 × = 30 E 21 = 500 230 200 × = 92 E 22 = 500 120 200 × = 48 E 23 = 500 100 200 × = 40 E 24 = 500 50 200 × = 20 Q = ( ) ( ) ( ) ( ) 30 30 25 60 60 70 72 72 75 138 138 130 2 2 2 2-+-+-+-( ) ( ) ( ) ( ) 20 20 25 40 40 30 48 48 45 92 92 100 2 2 2 2-+-+-+-+ = 7.72192 . ( 2 – 1 ) × ( 4 – 1 ) = 3 degrees of freedom 2 10 . χ ( 3 ) = 6.251 . 7.72192 > 6.251. Reject H at α = 0.10 p – value = 0.052122....
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This note was uploaded on 12/15/2011 for the course STAT 409 taught by Professor Stephanov during the Fall '11 term at University of Illinois at Urbana–Champaign.

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