Finding the Fourth Proportional to 12,687.85, 17,510.16 and 7,311.16

Step by Step Solution

1. Step 1: Write the proportion equation
   12,687.85 : 17,510.16 = 7,311.16 : x
2. Step 2: Convert to fraction form
   12,687.85/17,510.16 = 7,311.16/x
3. Step 3: Cross multiply
   12,687.85x = 17,510.16 × 7,311.16
4. Step 4: Simplify right side
   12,687.85x = 128,019,581.39
5. Step 5: Solve for x
   x = 128,019,581.39/12,687.85
6. Step 6: Final answer
   x = 10,089.93