Finding the Fourth Proportional to 3,399.28, 5,100.62 and 1,320.72

Step by Step Solution

1. Step 1: Write the proportion equation
   3,399.28 : 5,100.62 = 1,320.72 : x
2. Step 2: Convert to fraction form
   3,399.28/5,100.62 = 1,320.72/x
3. Step 3: Cross multiply
   3,399.28x = 5,100.62 × 1,320.72
4. Step 4: Simplify right side
   3,399.28x = 6,736,490.85
5. Step 5: Solve for x
   x = 6,736,490.85/3,399.28
6. Step 6: Final answer
   x = 1,981.74