Finding the Fourth Proportional to 2,586.80, 3,569.78 and 1,407.87

Step by Step Solution

1. Step 1: Write the proportion equation
   2,586.80 : 3,569.78 = 1,407.87 : x
2. Step 2: Convert to fraction form
   2,586.80/3,569.78 = 1,407.87/x
3. Step 3: Cross multiply
   2,586.80x = 3,569.78 × 1,407.87
4. Step 4: Simplify right side
   2,586.80x = 5,025,789.69
5. Step 5: Solve for x
   x = 5,025,789.69/2,586.80
6. Step 6: Final answer
   x = 1,942.86