Finding the Fourth Proportional to 3,651.20, 5,123.20 and 3,651.20

Step by Step Solution

1. Step 1: Write the proportion equation
   3,651.20 : 5,123.20 = 3,651.20 : x
2. Step 2: Convert to fraction form
   3,651.20/5,123.20 = 3,651.20/x
3. Step 3: Cross multiply
   3,651.20x = 5,123.20 × 3,651.20
4. Step 4: Simplify right side
   3,651.20x = 18,705,827.84
5. Step 5: Solve for x
   x = 18,705,827.84/3,651.20
6. Step 6: Final answer
   x = 5,123.20