document.write( "Question 752832: If mean of 100 numbers is 45. The mean that 99 numbers is 44 . What is the first number ? \n" ); document.write( "
Algebra.Com's Answer #458071 by Okeke_Christian(26)![]() ![]() You can put this solution on YOUR website! Formula for Mean (Average) = Sum of all numbers / Total number of numbers\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "Mean of 100 numbers = Sum of all hundred numbers / 100\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "We don't know the sum of all hundred numbers, so we call it x.\r \n" ); document.write( "\n" ); document.write( "From the question, mean of 100 numbers is 45. Therefore:\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "Cross Multiply: \n" ); document.write( " \n" ); document.write( "Therefore, the sum of those hundred numbers is 4,500.\r \n" ); document.write( "\n" ); document.write( "Now, \n" ); document.write( "Mean of 99 numbers = Sum of all ninety-nine numbers / 99\r \n" ); document.write( "\n" ); document.write( "We don't know the sum of all ninety-nine numbers, so we call it y.\r \n" ); document.write( "\n" ); document.write( "Mean of 99 numbers is equal to 44 so,\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "Cross Multiply: \n" ); document.write( " \n" ); document.write( "Therefore, the sum of the remaining ninety-nine numbers is 4356. \n" ); document.write( " \n" ); document.write( "Do you rememeber that when we had 100 numbers, the sum was 4,500? \n" ); document.write( "When we removed one number, the sum became 4,356. So, what was that number we removed?\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "144 is the first number! \n" ); document.write( " |