Finding the Fourth Proportional to 1,081.72, 1,492.98 and 689.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,081.72 : 1,492.98 = 689.20 : x
2. Step 2: Convert to fraction form
   1,081.72/1,492.98 = 689.20/x
3. Step 3: Cross multiply
   1,081.72x = 1,492.98 × 689.20
4. Step 4: Simplify right side
   1,081.72x = 1,028,961.82
5. Step 5: Solve for x
   x = 1,028,961.82/1,081.72
6. Step 6: Final answer
   x = 951.23