document.write( "Question 358806: A lottery has one $2000 prize, two $1000 prizes, and ten $500 prizes. Two thousand tickets are sold at $5 each. Find the expectation if a person buys two tickets? \n" ); document.write( "
Algebra.Com's Answer #256086 by jrfrunner(365)![]() ![]() You can put this solution on YOUR website! expectation is the same as the long term average value.\r \n" ); document.write( "\n" ); document.write( "values are the net return \n" ); document.write( "2000-5=1995 \n" ); document.write( "1000-5=995 \n" ); document.write( "500-5=495 \n" ); document.write( "-5=-5 \n" ); document.write( "you subtract 5 because the is the cost of playing and you dont get that back \n" ); document.write( "-- \n" ); document.write( "each of these occur with prob \n" ); document.write( "1/2000 \n" ); document.write( "2/2000 \n" ); document.write( "10/2000 \n" ); document.write( "1987/2000 \n" ); document.write( "-- \n" ); document.write( "so the expected value or long term average is sum (value*prob) \n" ); document.write( "=1995*(1/2000)+995*(2/2000)+495*(10/2000)+(-5)*(1987/2000)=-0.50 so on average you loose 0.50 for each ticket. If you buy 2 tickets your long term average is a loss of -1.00 dollar. \n" ); document.write( " |