Finding the Fourth Proportional to 12,581.72, 18,871.42 and 4,260.78

Step by Step Solution

1. Step 1: Write the proportion equation
   12,581.72 : 18,871.42 = 4,260.78 : x
2. Step 2: Convert to fraction form
   12,581.72/18,871.42 = 4,260.78/x
3. Step 3: Cross multiply
   12,581.72x = 18,871.42 × 4,260.78
4. Step 4: Simplify right side
   12,581.72x = 80,406,968.91
5. Step 5: Solve for x
   x = 80,406,968.91/12,581.72
6. Step 6: Final answer
   x = 6,390.78