Finding the Fourth Proportional to 12,389.76, 18,585.70 and 3,505.12

Step by Step Solution

1. Step 1: Write the proportion equation
   12,389.76 : 18,585.70 = 3,505.12 : x
2. Step 2: Convert to fraction form
   12,389.76/18,585.70 = 3,505.12/x
3. Step 3: Cross multiply
   12,389.76x = 18,585.70 × 3,505.12
4. Step 4: Simplify right side
   12,389.76x = 65,145,177.82
5. Step 5: Solve for x
   x = 65,145,177.82/12,389.76
6. Step 6: Final answer
   x = 5,257.99