document.write( "Question 1155685: Infinte Jackpot is a lottery game. 50 balls numbered 1 through 50 are placed in a machine and 4 of them are drawn at random. If the 4 numbers drawn match the numbers that a player had chosen, the player wins $50,000. In this lottery, the order the numbers are drawn in doesn’t matter. It costs 5 dollars to play. Compute the probability that you win the prize if you purchase a single lottery ticket. Also, calculate the expected value of this game. And determine whether it is a fair game. \n" ); document.write( "
Algebra.Com's Answer #778326 by ikleyn(52786)\"\" \"About 
You can put this solution on YOUR website!
.
\n" ); document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "The number of all quadruples of 4 numbered balls, randomly chosen from 50 numbered balls is\r\n" );
document.write( "\r\n" );
document.write( "    \"C%5B50%5D%5E4\" = \"%2850%2A49%2A48%2A47%29%2F%281%2A2%2A3%2A4%29\" = 230300.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "Of them, ONLY ONE group of balls is winning.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "So the probability to win is  \"1%2F230300\".\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "In all other  230300-230299 cases the gamer loses.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "Therefore. math expectation of the game is  \"50000%2F230300+-+5\" = -4.78 dollars.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "So, if you play this game MANY TIMES, you should expect to lose  4.78 dollars in each game, as average.\r\n" );
document.write( "
\r
\n" ); document.write( "\n" ); document.write( "-----------------\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The analysis is completed.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "For your safety, DO NOT PLAY THIS GAME (!)\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "--------------
\n" ); document.write( "Comment from student: can you show the steps on how to calculate the expected value, pls?!
\n" ); document.write( "--------------\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "My response.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Look into this Wikipedia article\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "https://en.wikipedia.org/wiki/Expected_value\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "and read couple of lines in the section \"Definition. Finite case\".\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );