Finding the Fourth Proportional to 1,107.31, 1,528.83 and 688.29

Step by Step Solution

1. Step 1: Write the proportion equation
   1,107.31 : 1,528.83 = 688.29 : x
2. Step 2: Convert to fraction form
   1,107.31/1,528.83 = 688.29/x
3. Step 3: Cross multiply
   1,107.31x = 1,528.83 × 688.29
4. Step 4: Simplify right side
   1,107.31x = 1,052,274.96
5. Step 5: Solve for x
   x = 1,052,274.96/1,107.31
6. Step 6: Final answer
   x = 950.30