Finding the Fourth Proportional to 3,709.78, 5,559.12 and 3,436.40

Step by Step Solution

1. Step 1: Write the proportion equation
   3,709.78 : 5,559.12 = 3,436.40 : x
2. Step 2: Convert to fraction form
   3,709.78/5,559.12 = 3,436.40/x
3. Step 3: Cross multiply
   3,709.78x = 5,559.12 × 3,436.40
4. Step 4: Simplify right side
   3,709.78x = 19,103,359.97
5. Step 5: Solve for x
   x = 19,103,359.97/3,709.78
6. Step 6: Final answer
   x = 5,149.46