Finding the Fourth Proportional to 21,200.72, 31,800.12 and 8,725.52

Step by Step Solution

1. Step 1: Write the proportion equation
   21,200.72 : 31,800.12 = 8,725.52 : x
2. Step 2: Convert to fraction form
   21,200.72/31,800.12 = 8,725.52/x
3. Step 3: Cross multiply
   21,200.72x = 31,800.12 × 8,725.52
4. Step 4: Simplify right side
   21,200.72x = 277,472,583.06
5. Step 5: Solve for x
   x = 277,472,583.06/21,200.72
6. Step 6: Final answer
   x = 13,087.88