Finding the Fourth Proportional to 105,477.38, 145,553.18 and 57,721.50

Step by Step Solution

1. Step 1: Write the proportion equation
   105,477.38 : 145,553.18 = 57,721.50 : x
2. Step 2: Convert to fraction form
   105,477.38/145,553.18 = 57,721.50/x
3. Step 3: Cross multiply
   105,477.38x = 145,553.18 × 57,721.50
4. Step 4: Simplify right side
   105,477.38x = 8,401,548,461.27
5. Step 5: Solve for x
   x = 8,401,548,461.27/105,477.38
6. Step 6: Final answer
   x = 79,652.61