document.write( "Question 79369: According to the CDC, if one member of the household contracts the
\n" ); document.write( "chickenpox, 90% of family member who have never had the disease or a
\n" ); document.write( "vaccine will contract the chickenpox. Suppose four members are exposed
\n" ); document.write( "for the first time. What is the probability that three or fewer family
\n" ); document.write( "members contract the chickenpox? \n" ); document.write( "
Algebra.Com's Answer #56965 by stanbon(75887)\"\" \"About 
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According to the CDC, if one member of the household contracts the chickenpox, 90% of family member who have never had the disease or a vaccine will contract the chickenpox. Suppose four members are exposed for the first time. What is the probability that three or fewer family members contract the chickenpox?
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\n" ); document.write( "It's a binomial problem with n=4, p=0.9, 0<=x<=3
\n" ); document.write( "If you have a TI calculator use binomcdf(4,0.9,3)=0.3439
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\n" ); document.write( "If you do not have a TI calculator use 1-P(4 contract the chickpox)
\n" ); document.write( "=1-4C4 (0.9)^4(0.1)^0= 1-0.6561=0.3439
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H. \r
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