Finding the Fourth Proportional to 1,085.55, 1,498.82 and 687.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,085.55 : 1,498.82 = 687.30 : x
2. Step 2: Convert to fraction form
   1,085.55/1,498.82 = 687.30/x
3. Step 3: Cross multiply
   1,085.55x = 1,498.82 × 687.30
4. Step 4: Simplify right side
   1,085.55x = 1,030,138.99
5. Step 5: Solve for x
   x = 1,030,138.99/1,085.55
6. Step 6: Final answer
   x = 948.96