document.write( "Question 1051630: 40% percent of households say they would feel secure if they had $50,000 in savings. You randomly select 88 households and ask them if they would feel secure if they had $50,000 in savings. Find the probability that the number that say they would feel secure is (a) exactly five, (b) more than five, and (c) at most five. \n" ); document.write( "

Algebra.Com's Answer #667096 by Boreal(15235) $\"\"$ $\"About$

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exactly 5 is 88C5(0.4)^5*0.6^83=1.5 X 10^(-13) or essentially 0.
\n" ); document.write( "4,3,2,1 will also be 0.
\n" ); document.write( "Therefore, c is 0.
\n" ); document.write( "b is 1.0
\n" ); document.write( "The expected value for 88 households is 88*0.4 or 35.2
\n" ); document.write( "The variation is 35.2*0.6 (np(1-p))=21.12, and the standard deviation is 4.6
\n" ); document.write( "5 households is 30.2/4.6, or 6.5 standard deviations below the mean.
\n" ); document.write( "Could the question be 8 households?
\n" ); document.write( "There the probability of 5 would be 8C50.4^5*0.6^3=0.124
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