Finding the Fourth Proportional to 2,439.69, 3,366.81 and 1,391.69

Step by Step Solution

1. Step 1: Write the proportion equation
   2,439.69 : 3,366.81 = 1,391.69 : x
2. Step 2: Convert to fraction form
   2,439.69/3,366.81 = 1,391.69/x
3. Step 3: Cross multiply
   2,439.69x = 3,366.81 × 1,391.69
4. Step 4: Simplify right side
   2,439.69x = 4,685,538.97
5. Step 5: Solve for x
   x = 4,685,538.97/2,439.69
6. Step 6: Final answer
   x = 1,920.55