Finding the Fourth Proportional to 2,639.87, 3,643.40 and 1,520.69

Step by Step Solution

1. Step 1: Write the proportion equation
   2,639.87 : 3,643.40 = 1,520.69 : x
2. Step 2: Convert to fraction form
   2,639.87/3,643.40 = 1,520.69/x
3. Step 3: Cross multiply
   2,639.87x = 3,643.40 × 1,520.69
4. Step 4: Simplify right side
   2,639.87x = 5,540,483.45
5. Step 5: Solve for x
   x = 5,540,483.45/2,639.87
6. Step 6: Final answer
   x = 2,098.78