document.write( "Question 348560: Two fair dice are rolled 5 times. Let the random variable x represent the number of times that the sum 7 occurs. The table below describes the probability distribution. Find the value of the missing probability.
\n" ); document.write( "x P(x)
\n" ); document.write( "0 0.401877572016461
\n" ); document.write( "1
\n" ); document.write( "2 0.160751028806584
\n" ); document.write( "3 0.0321502057613169
\n" ); document.write( "4 0.00321502057613169
\n" ); document.write( "5 0.000128600823045267 \n" ); document.write( "
Algebra.Com's Answer #249185 by Jk22(389)\"\" \"About 
You can put this solution on YOUR website!
the sum 7 is given by 1&6 2&5 3&4 and reverse order, hence 6 possibilities over 6*6=36
\n" ); document.write( "
\n" ); document.write( "so P(x)=(1/6)^x*(5/6)^(5-x)
\n" ); document.write( "
\n" ); document.write( "Verif : we find
\n" ); document.write( "P(5)=1/6^5=0.0001286
\n" ); document.write( "P(0)=(5/6)^5=0.4018
\n" ); document.write( "
\n" ); document.write( "however P(2) gives other result (0.01607 ?)
\n" ); document.write( "
\n" ); document.write( "P(1)=1/6*(5/6)^4=0.0803 \n" ); document.write( "
\n" );