Finding the Fourth Proportional to 105,140.08, 145,127.90 and 83,669.20

Step by Step Solution

1. Step 1: Write the proportion equation
   105,140.08 : 145,127.90 = 83,669.20 : x
2. Step 2: Convert to fraction form
   105,140.08/145,127.90 = 83,669.20/x
3. Step 3: Cross multiply
   105,140.08x = 145,127.90 × 83,669.20
4. Step 4: Simplify right side
   105,140.08x = 12,142,735,953.38
5. Step 5: Solve for x
   x = 12,142,735,953.38/105,140.08
6. Step 6: Final answer
   x = 115,491.03