Finding the Fourth Proportional to 105,040.92, 145,009.98 and 81,113.88

Step by Step Solution

1. Step 1: Write the proportion equation
   105,040.92 : 145,009.98 = 81,113.88 : x
2. Step 2: Convert to fraction form
   105,040.92/145,009.98 = 81,113.88/x
3. Step 3: Cross multiply
   105,040.92x = 145,009.98 × 81,113.88
4. Step 4: Simplify right side
   105,040.92x = 11,762,322,116.52
5. Step 5: Solve for x
   x = 11,762,322,116.52/105,040.92
6. Step 6: Final answer
   x = 111,978.48