Finding the Fourth Proportional to 1,080.52, 1,490.88 and 688.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,080.52 : 1,490.88 = 688.12 : x
2. Step 2: Convert to fraction form
   1,080.52/1,490.88 = 688.12/x
3. Step 3: Cross multiply
   1,080.52x = 1,490.88 × 688.12
4. Step 4: Simplify right side
   1,080.52x = 1,025,904.35
5. Step 5: Solve for x
   x = 1,025,904.35/1,080.52
6. Step 6: Final answer
   x = 949.45