Finding the Fourth Proportional to 128,404.50, 177,198.90 and 71,815.86

Step by Step Solution

1. Step 1: Write the proportion equation
   128,404.50 : 177,198.90 = 71,815.86 : x
2. Step 2: Convert to fraction form
   128,404.50/177,198.90 = 71,815.86/x
3. Step 3: Cross multiply
   128,404.50x = 177,198.90 × 71,815.86
4. Step 4: Simplify right side
   128,404.50x = 12,725,691,394.55
5. Step 5: Solve for x
   x = 12,725,691,394.55/128,404.50
6. Step 6: Final answer
   x = 99,106.27