Finding the Fourth Proportional to 10,870.55, 15,031.56 and 8,628.54

Step by Step Solution

1. Step 1: Write the proportion equation
   10,870.55 : 15,031.56 = 8,628.54 : x
2. Step 2: Convert to fraction form
   10,870.55/15,031.56 = 8,628.54/x
3. Step 3: Cross multiply
   10,870.55x = 15,031.56 × 8,628.54
4. Step 4: Simplify right side
   10,870.55x = 129,700,401.72
5. Step 5: Solve for x
   x = 129,700,401.72/10,870.55
6. Step 6: Final answer
   x = 11,931.35