Finding the Fourth Proportional to 21,112.62, 29,139.03 and 12,158.52

Step by Step Solution

1. Step 1: Write the proportion equation
   21,112.62 : 29,139.03 = 12,158.52 : x
2. Step 2: Convert to fraction form
   21,112.62/29,139.03 = 12,158.52/x
3. Step 3: Cross multiply
   21,112.62x = 29,139.03 × 12,158.52
4. Step 4: Simplify right side
   21,112.62x = 354,287,479.04
5. Step 5: Solve for x
   x = 354,287,479.04/21,112.62
6. Step 6: Final answer
   x = 16,780.84