Finding the Fourth Proportional to 1,086.87, 1,496.85 and 1,031.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,086.87 : 1,496.85 = 1,031.31 : x
2. Step 2: Convert to fraction form
   1,086.87/1,496.85 = 1,031.31/x
3. Step 3: Cross multiply
   1,086.87x = 1,496.85 × 1,031.31
4. Step 4: Simplify right side
   1,086.87x = 1,543,716.37
5. Step 5: Solve for x
   x = 1,543,716.37/1,086.87
6. Step 6: Final answer
   x = 1,420.33