document.write( "Question 1161983: The true proportion of residents at small barangay that favored the genuine opposition senatorial candidates is 85%. What is the probability that at least 75% of the 60 residents favored the genuine opposition? \n" ); document.write( "
Algebra.Com's Answer #785709 by Boreal(15235)\"\" \"About 
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can do with binomial, since very little remaining probability. This is pdf
\n" ); document.write( "p(44)=0.0077
\n" ); document.write( "p(43)=0.0035
\n" ); document.write( "p(42)=0.0015
\n" ); document.write( "p(41)=0.0006
\n" ); document.write( "P(40)=0.0002
\n" ); document.write( "cdf is1- binomcdf (60,.85,44) since we want 44 and everything less.
\n" ); document.write( "That is 0.9864 probability, the exact value\r
\n" ); document.write( "\n" ); document.write( "Normal approximation
\n" ); document.write( "The expected value is 51 (60*0.85)
\n" ); document.write( "the variance is np (1-p)=51(0.15)=7.65
\n" ); document.write( "sd is sqrt (V)=2.766
\n" ); document.write( "z>(44.5-51)/2.766=-2.35
\n" ); document.write( "probability is 0.9906 of z>=-2.36, a decent estimate\r
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