Finding the Fourth Proportional to 21,002.31, 31,503.15 and 8,522.28

Step by Step Solution

1. Step 1: Write the proportion equation
   21,002.31 : 31,503.15 = 8,522.28 : x
2. Step 2: Convert to fraction form
   21,002.31/31,503.15 = 8,522.28/x
3. Step 3: Cross multiply
   21,002.31x = 31,503.15 × 8,522.28
4. Step 4: Simplify right side
   21,002.31x = 268,478,665.18
5. Step 5: Solve for x
   x = 268,478,665.18/21,002.31
6. Step 6: Final answer
   x = 12,783.29