Finding the Fourth Proportional to 8,513.12, 12,737.28 and 5,123.18

Step by Step Solution

1. Step 1: Write the proportion equation
   8,513.12 : 12,737.28 = 5,123.18 : x
2. Step 2: Convert to fraction form
   8,513.12/12,737.28 = 5,123.18/x
3. Step 3: Cross multiply
   8,513.12x = 12,737.28 × 5,123.18
4. Step 4: Simplify right side
   8,513.12x = 65,255,378.15
5. Step 5: Solve for x
   x = 65,255,378.15/8,513.12
6. Step 6: Final answer
   x = 7,665.27