Finding the Fourth Proportional to 128,404.50, 177,198.81 and 71,815.89

Step by Step Solution

1. Step 1: Write the proportion equation
   128,404.50 : 177,198.81 = 71,815.89 : x
2. Step 2: Convert to fraction form
   128,404.50/177,198.81 = 71,815.89/x
3. Step 3: Cross multiply
   128,404.50x = 177,198.81 × 71,815.89
4. Step 4: Simplify right side
   128,404.50x = 12,725,690,247.09
5. Step 5: Solve for x
   x = 12,725,690,247.09/128,404.50
6. Step 6: Final answer
   x = 99,106.26