Finding the Fourth Proportional to 21,538.50, 29,724.96 and 12,108.89

Step by Step Solution

1. Step 1: Write the proportion equation
   21,538.50 : 29,724.96 = 12,108.89 : x
2. Step 2: Convert to fraction form
   21,538.50/29,724.96 = 12,108.89/x
3. Step 3: Cross multiply
   21,538.50x = 29,724.96 × 12,108.89
4. Step 4: Simplify right side
   21,538.50x = 359,936,270.89
5. Step 5: Solve for x
   x = 359,936,270.89/21,538.50
6. Step 6: Final answer
   x = 16,711.30