Finding the Fourth Proportional to 105,291.48, 144,936.09 and 91,839.31

Step by Step Solution

1. Step 1: Write the proportion equation
   105,291.48 : 144,936.09 = 91,839.31 : x
2. Step 2: Convert to fraction form
   105,291.48/144,936.09 = 91,839.31/x
3. Step 3: Cross multiply
   105,291.48x = 144,936.09 × 91,839.31
4. Step 4: Simplify right side
   105,291.48x = 13,310,830,137.36
5. Step 5: Solve for x
   x = 13,310,830,137.36/105,291.48
6. Step 6: Final answer
   x = 126,418.87