Finding the Fourth Proportional to 21,146.04, 31,709.94 and 8,658.30

Step by Step Solution

1. Step 1: Write the proportion equation
   21,146.04 : 31,709.94 = 8,658.30 : x
2. Step 2: Convert to fraction form
   21,146.04/31,709.94 = 8,658.30/x
3. Step 3: Cross multiply
   21,146.04x = 31,709.94 × 8,658.30
4. Step 4: Simplify right side
   21,146.04x = 274,554,173.50
5. Step 5: Solve for x
   x = 274,554,173.50/21,146.04
6. Step 6: Final answer
   x = 12,983.72