Finding the Fourth Proportional to 128,896.55, 193,269.89 and 86,250.71

Step by Step Solution

1. Step 1: Write the proportion equation
   128,896.55 : 193,269.89 = 86,250.71 : x
2. Step 2: Convert to fraction form
   128,896.55/193,269.89 = 86,250.71/x
3. Step 3: Cross multiply
   128,896.55x = 193,269.89 × 86,250.71
4. Step 4: Simplify right side
   128,896.55x = 16,669,665,234.12
5. Step 5: Solve for x
   x = 16,669,665,234.12/128,896.55
6. Step 6: Final answer
   x = 129,325.92