Finding the Fourth Proportional to 1,081.70, 1,491.86 and 688.04

Step by Step Solution

1. Step 1: Write the proportion equation
   1,081.70 : 1,491.86 = 688.04 : x
2. Step 2: Convert to fraction form
   1,081.70/1,491.86 = 688.04/x
3. Step 3: Cross multiply
   1,081.70x = 1,491.86 × 688.04
4. Step 4: Simplify right side
   1,081.70x = 1,026,459.35
5. Step 5: Solve for x
   x = 1,026,459.35/1,081.70
6. Step 6: Final answer
   x = 948.93