Finding the Fourth Proportional to 1,087.31, 1,499.83 and 644.92

Step by Step Solution

1. Step 1: Write the proportion equation
   1,087.31 : 1,499.83 = 644.92 : x
2. Step 2: Convert to fraction form
   1,087.31/1,499.83 = 644.92/x
3. Step 3: Cross multiply
   1,087.31x = 1,499.83 × 644.92
4. Step 4: Simplify right side
   1,087.31x = 967,265.00
5. Step 5: Solve for x
   x = 967,265.00/1,087.31
6. Step 6: Final answer
   x = 889.59