Finding the Fourth Proportional to 99,780.86, 137,700.42 and 54,461.72

Step by Step Solution

1. Step 1: Write the proportion equation
   99,780.86 : 137,700.42 = 54,461.72 : x
2. Step 2: Convert to fraction form
   99,780.86/137,700.42 = 54,461.72/x
3. Step 3: Cross multiply
   99,780.86x = 137,700.42 × 54,461.72
4. Step 4: Simplify right side
   99,780.86x = 7,499,401,717.92
5. Step 5: Solve for x
   x = 7,499,401,717.92/99,780.86
6. Step 6: Final answer
   x = 75,158.72