Finding the Fourth Proportional to 21,103.23, 29,123.91 and 12,153.09

Step by Step Solution

1. Step 1: Write the proportion equation
   21,103.23 : 29,123.91 = 12,153.09 : x
2. Step 2: Convert to fraction form
   21,103.23/29,123.91 = 12,153.09/x
3. Step 3: Cross multiply
   21,103.23x = 29,123.91 × 12,153.09
4. Step 4: Simplify right side
   21,103.23x = 353,945,499.38
5. Step 5: Solve for x
   x = 353,945,499.38/21,103.23
6. Step 6: Final answer
   x = 16,772.10