Finding the Fourth Proportional to 1,439.72, 2,158.81 and 699.08

Step by Step Solution

1. Step 1: Write the proportion equation
   1,439.72 : 2,158.81 = 699.08 : x
2. Step 2: Convert to fraction form
   1,439.72/2,158.81 = 699.08/x
3. Step 3: Cross multiply
   1,439.72x = 2,158.81 × 699.08
4. Step 4: Simplify right side
   1,439.72x = 1,509,180.89
5. Step 5: Solve for x
   x = 1,509,180.89/1,439.72
6. Step 6: Final answer
   x = 1,048.25