Finding the Fourth Proportional to 20,402.28, 28,162.17 and 12,861.32

Step by Step Solution

1. Step 1: Write the proportion equation
   20,402.28 : 28,162.17 = 12,861.32 : x
2. Step 2: Convert to fraction form
   20,402.28/28,162.17 = 12,861.32/x
3. Step 3: Cross multiply
   20,402.28x = 28,162.17 × 12,861.32
4. Step 4: Simplify right side
   20,402.28x = 362,202,539.45
5. Step 5: Solve for x
   x = 362,202,539.45/20,402.28
6. Step 6: Final answer
   x = 17,753.04