Finding the Fourth Proportional to 1,086.82, 1,499.46 and 644.71

Step by Step Solution

1. Step 1: Write the proportion equation
   1,086.82 : 1,499.46 = 644.71 : x
2. Step 2: Convert to fraction form
   1,086.82/1,499.46 = 644.71/x
3. Step 3: Cross multiply
   1,086.82x = 1,499.46 × 644.71
4. Step 4: Simplify right side
   1,086.82x = 966,717.13
5. Step 5: Solve for x
   x = 966,717.13/1,086.82
6. Step 6: Final answer
   x = 889.49