Finding the Fourth Proportional to 8,487.72, 12,729.15 and 5,157

Step by Step Solution

1. Step 1: Write the proportion equation
   8,487.72 : 12,729.15 = 5,157 : x
2. Step 2: Convert to fraction form
   8,487.72/12,729.15 = 5,157/x
3. Step 3: Cross multiply
   8,487.72x = 12,729.15 × 5,157
4. Step 4: Simplify right side
   8,487.72x = 65,644,226.55
5. Step 5: Solve for x
   x = 65,644,226.55/8,487.72
6. Step 6: Final answer
   x = 7,734.02