Finding the Fourth Proportional to 72,455.17, 99,872.61 and 57,116.71

Step by Step Solution

1. Step 1: Write the proportion equation
   72,455.17 : 99,872.61 = 57,116.71 : x
2. Step 2: Convert to fraction form
   72,455.17/99,872.61 = 57,116.71/x
3. Step 3: Cross multiply
   72,455.17x = 99,872.61 × 57,116.71
4. Step 4: Simplify right side
   72,455.17x = 5,704,394,902.31
5. Step 5: Solve for x
   x = 5,704,394,902.31/72,455.17
6. Step 6: Final answer
   x = 78,729.99