Finding the Fourth Proportional to 20,155.17, 27,826.59 and 12,987.62

Step by Step Solution

1. Step 1: Write the proportion equation
   20,155.17 : 27,826.59 = 12,987.62 : x
2. Step 2: Convert to fraction form
   20,155.17/27,826.59 = 12,987.62/x
3. Step 3: Cross multiply
   20,155.17x = 27,826.59 × 12,987.62
4. Step 4: Simplify right side
   20,155.17x = 361,401,117.68
5. Step 5: Solve for x
   x = 361,401,117.68/20,155.17
6. Step 6: Final answer
   x = 17,930.94