Finding the Fourth Proportional to 12,486.72, 18,732.24 and 3,720.72

Step by Step Solution

1. Step 1: Write the proportion equation
   12,486.72 : 18,732.24 = 3,720.72 : x
2. Step 2: Convert to fraction form
   12,486.72/18,732.24 = 3,720.72/x
3. Step 3: Cross multiply
   12,486.72x = 18,732.24 × 3,720.72
4. Step 4: Simplify right side
   12,486.72x = 69,697,420.01
5. Step 5: Solve for x
   x = 69,697,420.01/12,486.72
6. Step 6: Final answer
   x = 5,581.72