Finding the Fourth Proportional to 10,890.20, 15,031.86 and 8,656.04

Step by Step Solution

1. Step 1: Write the proportion equation
   10,890.20 : 15,031.86 = 8,656.04 : x
2. Step 2: Convert to fraction form
   10,890.20/15,031.86 = 8,656.04/x
3. Step 3: Cross multiply
   10,890.20x = 15,031.86 × 8,656.04
4. Step 4: Simplify right side
   10,890.20x = 130,116,381.43
5. Step 5: Solve for x
   x = 130,116,381.43/10,890.20
6. Step 6: Final answer
   x = 11,948.02