Finding the Fourth Proportional to 1,081.15, 1,491.01 and 687.49

Step by Step Solution

1. Step 1: Write the proportion equation
   1,081.15 : 1,491.01 = 687.49 : x
2. Step 2: Convert to fraction form
   1,081.15/1,491.01 = 687.49/x
3. Step 3: Cross multiply
   1,081.15x = 1,491.01 × 687.49
4. Step 4: Simplify right side
   1,081.15x = 1,025,054.46
5. Step 5: Solve for x
   x = 1,025,054.46/1,081.15
6. Step 6: Final answer
   x = 948.11