Finding the Fourth Proportional to 31,978.94, 47,961.12 and 8,607.20

Step by Step Solution

1. Step 1: Write the proportion equation
   31,978.94 : 47,961.12 = 8,607.20 : x
2. Step 2: Convert to fraction form
   31,978.94/47,961.12 = 8,607.20/x
3. Step 3: Cross multiply
   31,978.94x = 47,961.12 × 8,607.20
4. Step 4: Simplify right side
   31,978.94x = 412,810,952.06
5. Step 5: Solve for x
   x = 412,810,952.06/31,978.94
6. Step 6: Final answer
   x = 12,908.84