Finding the Fourth Proportional to 20,143.18, 27,801.56 and 12,870.62

Step by Step Solution

1. Step 1: Write the proportion equation
   20,143.18 : 27,801.56 = 12,870.62 : x
2. Step 2: Convert to fraction form
   20,143.18/27,801.56 = 12,870.62/x
3. Step 3: Cross multiply
   20,143.18x = 27,801.56 × 12,870.62
4. Step 4: Simplify right side
   20,143.18x = 357,823,142.98
5. Step 5: Solve for x
   x = 357,823,142.98/20,143.18
6. Step 6: Final answer
   x = 17,763.99