Finding the Fourth Proportional to 1,081.18, 1,492.28 and 688.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,081.18 : 1,492.28 = 688.15 : x
2. Step 2: Convert to fraction form
   1,081.18/1,492.28 = 688.15/x
3. Step 3: Cross multiply
   1,081.18x = 1,492.28 × 688.15
4. Step 4: Simplify right side
   1,081.18x = 1,026,912.48
5. Step 5: Solve for x
   x = 1,026,912.48/1,081.18
6. Step 6: Final answer
   x = 949.81