Finding the Fourth Proportional to 20,925.47, 31,394.27 and 8,439.05

Step by Step Solution

1. Step 1: Write the proportion equation
   20,925.47 : 31,394.27 = 8,439.05 : x
2. Step 2: Convert to fraction form
   20,925.47/31,394.27 = 8,439.05/x
3. Step 3: Cross multiply
   20,925.47x = 31,394.27 × 8,439.05
4. Step 4: Simplify right side
   20,925.47x = 264,937,913.83
5. Step 5: Solve for x
   x = 264,937,913.83/20,925.47
6. Step 6: Final answer
   x = 12,661.02