Finding the Fourth Proportional to 2,278.20, 3,142.86 and 1,439.96

Step by Step Solution

1. Step 1: Write the proportion equation
   2,278.20 : 3,142.86 = 1,439.96 : x
2. Step 2: Convert to fraction form
   2,278.20/3,142.86 = 1,439.96/x
3. Step 3: Cross multiply
   2,278.20x = 3,142.86 × 1,439.96
4. Step 4: Simplify right side
   2,278.20x = 4,525,592.69
5. Step 5: Solve for x
   x = 4,525,592.69/2,278.20
6. Step 6: Final answer
   x = 1,986.48