Finding the Fourth Proportional to 8,707.02, 12,018.15 and 5,172.72

Step by Step Solution

1. Step 1: Write the proportion equation
   8,707.02 : 12,018.15 = 5,172.72 : x
2. Step 2: Convert to fraction form
   8,707.02/12,018.15 = 5,172.72/x
3. Step 3: Cross multiply
   8,707.02x = 12,018.15 × 5,172.72
4. Step 4: Simplify right side
   8,707.02x = 62,166,524.87
5. Step 5: Solve for x
   x = 62,166,524.87/8,707.02
6. Step 6: Final answer
   x = 7,139.82