Finding the Fourth Proportional to 105,908.31, 146,210.21 and 81,656.30

Step by Step Solution

1. Step 1: Write the proportion equation
   105,908.31 : 146,210.21 = 81,656.30 : x
2. Step 2: Convert to fraction form
   105,908.31/146,210.21 = 81,656.30/x
3. Step 3: Cross multiply
   105,908.31x = 146,210.21 × 81,656.30
4. Step 4: Simplify right side
   105,908.31x = 11,938,985,493.59
5. Step 5: Solve for x
   x = 11,938,985,493.59/105,908.31
6. Step 6: Final answer
   x = 112,729.45