Finding the Fourth Proportional to 5,738.40, 7,920.72 and 3,643.20

Step by Step Solution

1. Step 1: Write the proportion equation
   5,738.40 : 7,920.72 = 3,643.20 : x
2. Step 2: Convert to fraction form
   5,738.40/7,920.72 = 3,643.20/x
3. Step 3: Cross multiply
   5,738.40x = 7,920.72 × 3,643.20
4. Step 4: Simplify right side
   5,738.40x = 28,856,767.10
5. Step 5: Solve for x
   x = 28,856,767.10/5,738.40
6. Step 6: Final answer
   x = 5,028.71