Finding the Fourth Proportional to 87,128.96, 120,239.20 and 65,286.56

Step by Step Solution

1. Step 1: Write the proportion equation
   87,128.96 : 120,239.20 = 65,286.56 : x
2. Step 2: Convert to fraction form
   87,128.96/120,239.20 = 65,286.56/x
3. Step 3: Cross multiply
   87,128.96x = 120,239.20 × 65,286.56
4. Step 4: Simplify right side
   87,128.96x = 7,850,003,745.15
5. Step 5: Solve for x
   x = 7,850,003,745.15/87,128.96
6. Step 6: Final answer
   x = 90,096.38