Finding the Fourth Proportional to 20,142.15, 30,204.72 and 10,780.17

Step by Step Solution

1. Step 1: Write the proportion equation
   20,142.15 : 30,204.72 = 10,780.17 : x
2. Step 2: Convert to fraction form
   20,142.15/30,204.72 = 10,780.17/x
3. Step 3: Cross multiply
   20,142.15x = 30,204.72 × 10,780.17
4. Step 4: Simplify right side
   20,142.15x = 325,612,016.40
5. Step 5: Solve for x
   x = 325,612,016.40/20,142.15
6. Step 6: Final answer
   x = 16,165.70