Finding the Fourth Proportional to 1,108.31, 1,530.24 and 688.85

Step by Step Solution

1. Step 1: Write the proportion equation
   1,108.31 : 1,530.24 = 688.85 : x
2. Step 2: Convert to fraction form
   1,108.31/1,530.24 = 688.85/x
3. Step 3: Cross multiply
   1,108.31x = 1,530.24 × 688.85
4. Step 4: Simplify right side
   1,108.31x = 1,054,106.78
5. Step 5: Solve for x
   x = 1,054,106.78/1,108.31
6. Step 6: Final answer
   x = 951.09