Finding the Fourth Proportional to 1,086.97, 1,500.04 and 644.86

Step by Step Solution

1. Step 1: Write the proportion equation
   1,086.97 : 1,500.04 = 644.86 : x
2. Step 2: Convert to fraction form
   1,086.97/1,500.04 = 644.86/x
3. Step 3: Cross multiply
   1,086.97x = 1,500.04 × 644.86
4. Step 4: Simplify right side
   1,086.97x = 967,308.82
5. Step 5: Solve for x
   x = 967,308.82/1,086.97
6. Step 6: Final answer
   x = 889.92