Finding the Fourth Proportional to 21,671.28, 29,906.01 and 12,111.39

Step by Step Solution

1. Step 1: Write the proportion equation
   21,671.28 : 29,906.01 = 12,111.39 : x
2. Step 2: Convert to fraction form
   21,671.28/29,906.01 = 12,111.39/x
3. Step 3: Cross multiply
   21,671.28x = 29,906.01 × 12,111.39
4. Step 4: Simplify right side
   21,671.28x = 362,203,350.45
5. Step 5: Solve for x
   x = 362,203,350.45/21,671.28
6. Step 6: Final answer
   x = 16,713.52