Finding the Fourth Proportional to 21,061.98, 31,592.84 and 8,581.77

Step by Step Solution

1. Step 1: Write the proportion equation
   21,061.98 : 31,592.84 = 8,581.77 : x
2. Step 2: Convert to fraction form
   21,061.98/31,592.84 = 8,581.77/x
3. Step 3: Cross multiply
   21,061.98x = 31,592.84 × 8,581.77
4. Step 4: Simplify right side
   21,061.98x = 271,122,443.62
5. Step 5: Solve for x
   x = 271,122,443.62/21,061.98
6. Step 6: Final answer
   x = 12,872.60