Finding the Fourth Proportional to 2,385.57, 3,579.57 and 1,086.87

Step by Step Solution

1. Step 1: Write the proportion equation
   2,385.57 : 3,579.57 = 1,086.87 : x
2. Step 2: Convert to fraction form
   2,385.57/3,579.57 = 1,086.87/x
3. Step 3: Cross multiply
   2,385.57x = 3,579.57 × 1,086.87
4. Step 4: Simplify right side
   2,385.57x = 3,890,527.25
5. Step 5: Solve for x
   x = 3,890,527.25/2,385.57
6. Step 6: Final answer
   x = 1,630.86