Finding the Fourth Proportional to 3,691.38, 5,496.09 and 3,639.72

Step by Step Solution

1. Step 1: Write the proportion equation
   3,691.38 : 5,496.09 = 3,639.72 : x
2. Step 2: Convert to fraction form
   3,691.38/5,496.09 = 3,639.72/x
3. Step 3: Cross multiply
   3,691.38x = 5,496.09 × 3,639.72
4. Step 4: Simplify right side
   3,691.38x = 20,004,228.69
5. Step 5: Solve for x
   x = 20,004,228.69/3,691.38
6. Step 6: Final answer
   x = 5,419.17