Finding the Fourth Proportional to 2,439.59, 3,366.59 and 1,391.63

Step by Step Solution

1. Step 1: Write the proportion equation
   2,439.59 : 3,366.59 = 1,391.63 : x
2. Step 2: Convert to fraction form
   2,439.59/3,366.59 = 1,391.63/x
3. Step 3: Cross multiply
   2,439.59x = 3,366.59 × 1,391.63
4. Step 4: Simplify right side
   2,439.59x = 4,685,023.85
5. Step 5: Solve for x
   x = 4,685,023.85/2,439.59
6. Step 6: Final answer
   x = 1,920.42