Finding the Fourth Proportional to 87,399.50, 120,546.78 and 64,739.43

Step by Step Solution

1. Step 1: Write the proportion equation
   87,399.50 : 120,546.78 = 64,739.43 : x
2. Step 2: Convert to fraction form
   87,399.50/120,546.78 = 64,739.43/x
3. Step 3: Cross multiply
   87,399.50x = 120,546.78 × 64,739.43
4. Step 4: Simplify right side
   87,399.50x = 7,804,129,825.54
5. Step 5: Solve for x
   x = 7,804,129,825.54/87,399.50
6. Step 6: Final answer
   x = 89,292.62