# 409Quiz5Dans - p YA p XB = p YB p XAB = p YAB E 11 = 500...

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STAT 409 Fall 2011 Name ANSWERS . Version D 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 120 85 60 35 300 Town Y 100 45 30 25 200 220 130 90 60 500 Use α = 0.05 to test H 0 : p XO = p YO , p XA =
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Unformatted text preview: p YA , p XB = p YB , p XAB = p YAB . E 11 = 500 220 300 × = 132 E 12 = 500 130 300 × = 78 E 13 = 500 90 300 × = 54 E 14 = 500 60 300 × = 36 E 21 = 500 220 200 × = 88 E 22 = 500 130 200 × = 52 E 23 = 500 90 200 × = 36 E 24 = 500 60 200 × = 24 Q = ( ) ( ) ( ) ( ) 36 36 35 54 54 60 78 78 85 132 132 120 2 2 2 2-+-+-+-( ) ( ) ( ) ( ) 24 24 25 36 36 30 52 52 45 88 88 100 2 2 2 2-+-+-+-+ = 6.033897 . ( 2 – 1 ) × ( 4 – 1 ) = 3 degrees of freedom 2 05 . χ ( 3 ) = 7.815 . 6.033897 < 7.815. Do NOT Reject H at α = 0.05 p – value = 0.109973....
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