Finding the Fourth Proportional to 21,057.59, 29,059.47 and 12,106.85

Step by Step Solution

1. Step 1: Write the proportion equation
   21,057.59 : 29,059.47 = 12,106.85 : x
2. Step 2: Convert to fraction form
   21,057.59/29,059.47 = 12,106.85/x
3. Step 3: Cross multiply
   21,057.59x = 29,059.47 × 12,106.85
4. Step 4: Simplify right side
   21,057.59x = 351,818,499.07
5. Step 5: Solve for x
   x = 351,818,499.07/21,057.59
6. Step 6: Final answer
   x = 16,707.44