Finding the Fourth Proportional to 85,472.42, 128,204.78 and 57,404.30

Step by Step Solution

1. Step 1: Write the proportion equation
   85,472.42 : 128,204.78 = 57,404.30 : x
2. Step 2: Convert to fraction form
   85,472.42/128,204.78 = 57,404.30/x
3. Step 3: Cross multiply
   85,472.42x = 128,204.78 × 57,404.30
4. Step 4: Simplify right side
   85,472.42x = 7,359,504,724.51
5. Step 5: Solve for x
   x = 7,359,504,724.51/85,472.42
6. Step 6: Final answer
   x = 86,103.86