Finding the Fourth Proportional to 85,411.35, 128,195.40 and 43,320.72

Step by Step Solution

1. Step 1: Write the proportion equation
   85,411.35 : 128,195.40 = 43,320.72 : x
2. Step 2: Convert to fraction form
   85,411.35/128,195.40 = 43,320.72/x
3. Step 3: Cross multiply
   85,411.35x = 128,195.40 × 43,320.72
4. Step 4: Simplify right side
   85,411.35x = 5,553,517,028.69
5. Step 5: Solve for x
   x = 5,553,517,028.69/85,411.35
6. Step 6: Final answer
   x = 65,020.83