Finding the Fourth Proportional to 21,711.18, 29,960.91 and 12,151.20

Step by Step Solution

1. Step 1: Write the proportion equation
   21,711.18 : 29,960.91 = 12,151.20 : x
2. Step 2: Convert to fraction form
   21,711.18/29,960.91 = 12,151.20/x
3. Step 3: Cross multiply
   21,711.18x = 29,960.91 × 12,151.20
4. Step 4: Simplify right side
   21,711.18x = 364,061,009.59
5. Step 5: Solve for x
   x = 364,061,009.59/21,711.18
6. Step 6: Final answer
   x = 16,768.37