Finding the Fourth Proportional to 21,702.78, 29,949.72 and 12,142.67

Step by Step Solution

1. Step 1: Write the proportion equation
   21,702.78 : 29,949.72 = 12,142.67 : x
2. Step 2: Convert to fraction form
   21,702.78/29,949.72 = 12,142.67/x
3. Step 3: Cross multiply
   21,702.78x = 29,949.72 × 12,142.67
4. Step 4: Simplify right side
   21,702.78x = 363,669,416.80
5. Step 5: Solve for x
   x = 363,669,416.80/21,702.78
6. Step 6: Final answer
   x = 16,756.81