Finding the Fourth Proportional to 72,456.18, 99,873.98 and 57,117.72

Step by Step Solution

1. Step 1: Write the proportion equation
   72,456.18 : 99,873.98 = 57,117.72 : x
2. Step 2: Convert to fraction form
   72,456.18/99,873.98 = 57,117.72/x
3. Step 3: Cross multiply
   72,456.18x = 99,873.98 × 57,117.72
4. Step 4: Simplify right side
   72,456.18x = 5,704,574,024.93
5. Step 5: Solve for x
   x = 5,704,574,024.93/72,456.18
6. Step 6: Final answer
   x = 78,731.37